Tuesday, December 21, 2010

Happy Winter Solstice!

Yes, today (Dec. 21, 2010) is the first day of winter. We can tell. Here in Sarasota we've had bone-chilling temperatures in the 40s and 50s (Fahrenheit, of course) and on a couple evenings it even dipped into the 30s. But, your writer (Harry) grew up near Buffalo, so I guess I can handle it.

Holiday Greetings.

It's a wonderful time of the year, whatever your beliefs. I was raised in the Christian tradition. So (and without any commercial benefit whatever, since I don't believe many people give signal conditioners as Christmas presents), I'm not ashamed to say:

Merry Christmas.

Christian beliefs include the Old Testament. Hannukah celebrates religious freedom. Judas Maccabeus led the revolt which restored the right of the Jews to practice their religion at the temple in Jerusalem. Hanukkah celebrates the miracle that one day's worth of lamp oil lasted 8 days. So, to our Jewish friends includng Bea next door and Myra and Stan down the steet, I wish you (belatedly):

Happy Hanukkah.

Kwanzaa, while not a religious holiday, celebrates the 7 principles of Unity, Self Determination, Collective Work and Responsibility, Cooperative Economics, Purpose, Creativity and Faith, wonderful guiding principles for communities of any  belief or nationality. To our friends who celebrate it:

Joyous Kwanzaa, and Habari Gani?


I once worked with a fellow who claimed to be a Pagan. Of course, the timing of the Christmas celebration and some of its traditions (such as the Christmas tree) evolved from pagan winter solstice traditions (which is part of the reason the early Puritans forbade its celebration), So to all of you who may be pagans, non-religious or perhaps just tired of the excesses of the season:

Happy Winter Solstice.

(My apologies to those of other beliefs that I am not familiar with.)

And - an early Happy New Year from Harry and all of us at JH Technology.



Wednesday, December 1, 2010

Minisystem Measures Gas Flow

Custom Mass Flow (Gas) Minisystem


Not new - we did this one a few years ago - but here's an example of what we can do.

An Alcoa extrusions plant in Spanish Point, Utah had been monitoring natural gas usage with turbine flowmeters (volumetric) but wished to convert to mass flow for improved accuracy. The turbine manufacturer could have provided a compensated measurement, but only if the flowmeters were replaced. As these were 3 and 4 inch meters replacement costs would have been high, and piping changes would have been needed. Alcoa needed a less-expensive solution.

Alcoa added temperature and pressure sensors to the gas lines, and JH Technology was able to create a mass flow Minisystem using signal conditioners. Five modules convert the turbine pulses to DC, perform multiplication and division, produce both 4-20mAdc and pulse rate outputs proportional to mass flow in SCFH (Standard Cubic Feet per Hour) and provide 24Vdc power to the pressure and temperature sensors. The modules were premounted and wired on a panel and placed inside a NEMA-4 field enclosure.

Alcoa reported that the system provided significant savings compared to the costs of new flowmeters, and even more by eliminating the need for piping changes.

To read the complete application note, click here.

Links: Our Specials & Minisystems page
Application Notes index
All JH Technology signal conditioners

Monday, November 22, 2010

Thanksgiving 2010

Thanksgiving

We've a lot to be thankful for this year. First and foremost, of course, our families, friends and health. We all have our individual families plus, our "family" at JH Technology.

We're grateful, of course, to our customers, but we also appreciate those of you who are interested in what we do even though you may not have needs or opportunities we can meet at this time.

We're thankful this year that we have grown despite the economy. We're almost back to where we were before last year's "dip". We appreciate our employees who took some temporary pay reductions last year and for our suppliers who were understanding when we ran behind on payments.

And, despite what your feelings may be regarding the politics of the moment, we're especially thankful to be able to live and work in America. We aren't perfect or always right and we have our problems and disagreements, but still we're fortunate to live in one of the best places in the world.

Give thanks - to your friends and family, to those who love you, to whatever god or deity you may believe in - and be grateful for what we all have been given.

Happy Thanksging

From Harry and all of us at JH Technology.

Sunday, November 7, 2010

Speaking of Specials - - -

Pulse Amplifier:
Special Product - leads to a second special - then two standard products - and then yet a third special!

A bit of "fun" history here - our standard Models JH376 & JH377 were introduced  last year (blog entry October 10, 2009).

In 2001 an engineer at a Canadian company - lets call it "Company A" - contacted us. They were using another manufacturer's pulse amplifier which worked but was inconvenient to mount in their system. We quoted, designed and sold them a functional equivalent in a DIN-rail mount case. The engineer later left and the orders stopped.

The same engineer called us in 2004, now with a different firm ("Company B") and with a modified set of requirements. He needed different - and adjustable - sensitivity, different filtering and the ability to accommodate both mag pickup and logic pulse inputs. We worked with him to prototype and develop a new design. They ordered regularly for about two years but then, early 2007, the orders stopped. (We later learned he'd gone back to "Company A".)

So - we now had a design but no customers. We decided to "run it up the flagpole" as a standard product and see what happened. After reviewing both companies' requirements plus competitive products we revised the standard product's filtering and sensitivity specs a bit. Introduced a year ago, it's been a modest success including a new OEM customer.

And now. "the rest of the story". In August "Company B" called again. They reordered their version but really wanted yet a different set of requirements. We again worked with them to develop a new version which they have since bought. We also contacted the original engineer at "Company A" but their systems have changed and they no longer need pulse amplifiers.

Our standard products (with links):
Pulse Amplifier: Model JH376, optimized for use with mag-coil type magnetic pickups.
Pulse Converter: Model JH377, optimized for use with logic pulse and open-collector inputs.
Or, if you need specials, contact us - jhtek@jhtechnology, (800) 808-0300 or (941) 927-0300,

Our web site: http://www.jhtechnology.com/

Saturday, September 25, 2010

Sarasota Arts Scene - Jazz

From Harry this week - personal interest.


For a small city, Sarasota has an incredibly vibrant arts scene. Here's an example.


My wife, Jacquie, and I went to a jazz concert at a local church. A six-piece group, they performed incredibly well. Their ages - 13 to 17 years old, and they've been around three years. From their publicity:

"They created the group three years ago, playing jazz in front of a local grocery store on Saturday mornings. Seeing how determined they were, Greg Nielsen, a jazz trombonist, took them under his wing and has been coaching them ever since."

They've made several television appearances including the Grammy awards and, this past summer, appeared at three European jazz festivals including Montreux in Switzerland. (The cost - $35.000.) The thirteen year old is the very petite female trumpeter/vocalist. It's surprising to see such power (both trumpet and voice) from such a small girl. An audience member told us she started the group at age nine. She's incredible - from the on-stage appearance it seems like she's the leader. Three previous members of the group have graduated and gone on to college.

Anyway, as I said, personal interest this week. If you're interested here's a link to their site, complete with videos.

http://www.jazzjuvenocracy.com/

Saturday, September 18, 2010

Discontinued Action-Paks? Call us.

As most of you know, many years ago Action Instruments introduced plug-in "Action-Pak" transmitters and alarms.(Note: Action-Pak is an Action Instruments trademark.) Action grew, became a highly regarded company, added other product lines and were eventually acquired by Eurotherm. Their line still includes Action-Paks but some models are no longer available.

One of our favorite stories - a company called us desperately looking for a special version of an old Action module. They told us, not only could Action no longer make it, they insisted they never had! The customer forwarded us a copy of Action's user's manual.

OK - a special - a one-piece order - we had to charge for some engineering, but we did it. They've ordered a few more since.

Over ten years ago another company came to us because Action no longer made some of the (standard) products they used regularly. Our product line included them (still does) and that company has become one of our better customers.

We're not trying to knock Action. They are a well-respected, quality company. But if you need plug-in modules they no longer offer, e-mail or call us. We probably can help. (And, our customers rave about our service.)

Signal Conditioners - our web site: http://www.jhtechnology.com/
e-mail: jhtek@jhtechnology.com
Phone: (941) 927-0300 or US toll-free (800) 808-0300
Fax: (941) 925-8774

Sunday, September 5, 2010

Political Ads - Lying is Legal

From Harry -

Here in Florida we just finished a typical primary campaign featuring two Republican candidates for Governor, and two Democratic candidates for Senate, heaping piles of dirt on each other. I got to thinking - somewhere in the past I'd read that court decisions had declared lying in political ads to be protected by the Constitution.

After strenuous research (meaning 30 seconds on Yahoo) I found I was right. What's worse, the Federal Communications Act prohibits broadcasters from refusing to run specific ads - even those known to be untrue - unless they refuse all political advertising. If you're interested, here's a link to a 2008 Time Magazine article on the subject.

Truth in Advertising? Not for Political Ads

Don't believe everything you hear!

Monday, August 30, 2010

Thermocouple Application Note

Unusual Thermocouple Application


Our customer's client had a large spa facility. The controls had been located near the spa, but the client felt they should be moved to a more benign environment, several hundred feet away. The system included four thermocouples. Sending thermocouple signals this distance is expensive, since thermocouple wire (not copper) must be used. Even more basic, sending weak millivolt signals hundreds of feet leaves them subject to interference and signal degradation.

To boost the signals, four standard thermocouple transmitters (our Model JH4130) were added near the spa. Their 4-20mA current signals easily traveled the distance with no degradation. The system designers opted not to change the control system, so it was necessary to convert the current signals back to their original thermocouple voltages. "Reverse" thermocouple transmitters, 4-20mA input, thermocouple output, were needed.

We provided them. We modified our Model JH4300 DC input, DC output transmitters to have the proper millivolt outputs. The most interesting challenge was, the millivolt outputs needed to be connected to thermocouple wires (not copper) for proper connection to the system's thermocouple inputs. This called for the reverse of cold junction compensation (we called it "cold junction un-compensation"). A temperature sensor embedded in the output terminals and some properly-designed circuitry solved the problem

Temperature Transmitters & Signal Conditioners - our web site: http://www.jhtechnology.com/

Sunday, August 8, 2010

Application Note

AC to DC Translation Monitors Shaker Motion

Here's an application we did 10 years ago for a major manufacturer of membrane-based filtration equipment. They're still using it.

The need - to monitor and control filter movement. Motorized systems are used to oscillate large filter elements back and forth. Peak-to-peak motion is controlled using motor drives. Motion is continuously monitored using laser-based displacement (position) measurement equipment.

The problem – the laser’s output represents instantaneous position, varying continuously as the filter shakes back and forth. The company needed to convert peak-to-peak displacement to 4-20mAdc input current for the motor drive controllers.

The solution – our Model JH5600 AC Input Transmitter. Because the filters are large and driven by rotating equipment their motion is purely sinusoidal so the relationships between average, RMS and peak values are well known. In this application an input range of 0 to 3.536 volts RMS (odd ranges are not special for us) corresponds to 0 to 10 volts peak-to-peak. We have in the past created special modifications for true peak-to-peak measurement, but this was not required for this application

For those who prefer plug-in style modules, the same function is available in our Model JH6010I.




AC Input Transmitters, Signal Conditioners - our web site: http://www.jhtechnology.com/
 
JH5600 data sheet: www.jhtechnology.com/dinrail_tx/jh5600_5610.htm

Tuesday, July 13, 2010

New Products

Integrators
(DC to Frequency Converters)

Brand-new Models JH7500 & JH7501 integrators convert a DC measurement signal (voltage or current) to a proportional frequency. JH7500 is the general-purpose version. JH7501 operates at low pulse rates - its output is a set of relay contacts that 'click' at the output pulse rate.

Integrator - why the name?

The original - and still common - application is to totalize, or "integrate" flow measurements. A signal from a flowmeter represents flow rate (such as gallons per minute). Each output pulse represents a fixed quantity (such as a gallon, fraction of a gallon or number of gallons). The pulses are fed to a counter. The faster the flow the faster the pulses, so the total flow may be found by reading the counter. Similarly, if the input represents instantaneous power (kilowatts) the total represents power usage (kilowatt-hours).

More modern applications include signal conversion (convert a DC measurement signal to frequency for a PLC's input) and tone telemetry (transmit the converted frequency over a distance, then convert it back to DC at the receiving eng. JH Technology offers frequency to DC converters (also called frequency input transmitters) to perform the receiving end conversion.

For product details click:
JH7500/JH7501 Integrators (DC to Frequency Converters
JH7010I Frequency to DC Converter (Plug-in style, fixed range)
JH7580 Frequency to DC Converter (Plug-in style, user rangeable)
JH5700 Frequency to DC Converter (DIN-rail style, fixed range)

Our web site: http://www.jhtechnology.com/

Thursday, June 17, 2010

New from JH Technology

FAST Response!

Transmitters with 1 millisecond response time.

Last year we spotlighted a new design we'd done for a customer needing a quantity of fast-response transmitters. We've now turned it into a standard product offering.



Available on most of our DIN-rail transmitters (JH5000 Series), Option HS output is approximately complete (95% response) in 0.001 seconds. It is not available on AC input or frequency input transmitters, as these require filtering to function properly.

Frequency response is 3dB down (0.707 times the DC gain) at approximately 600 Hz.

Faster (or slower) available - contact us!


Sunday, June 13, 2010

Custom Designs

A Very Special Special

A well-known company needed to duplicate a thermocouple alarm they had bought from Action Instruments decades ago. Action was no longer able to provide it so they turned to us.

Action's original "Action Pak" line (Action's trademark) once included alarm modules with extra options such as retransmitting outputs and remote setpoint inputs. 20-pin headers (pin bases) were required to provide the extra connections. As far as we are aware these headers are no longer available.

Our customer's requirement was a nonstandard version of one of those alarms. We replied that we could provide the same function but with a different connection arrangement. This was not acceptable - it was for a nuclear power application and they could not vary the system design. Only one piece, but they were willing to pay for it.

Once again we got lucky. In 1995 we had purchased some 20 pin headers for another customer's need and had a handful left. Our customer bought one (couldn't convince them to buy a spare) - even sent an inspector to Florida to do a source inspection. That was 2008. In 2009 they again bought one and just now ordered two more! Possible future problem - after this order we have only five headers left.

(Note: We do not sell nuclear-approved products. This alarm was sold as "standard commercial quality" for a noncritical application.)

Technical detail: the custom alarm module has two retransmitting 0-1V analog outputs, one proportional to temperature and the other proportional to the setpoint. Our customer was able to supply us with Action's specifications and we designed it to be functionally identical. Here's the functional diagram.



If you have special requirements let us know. Phone (941) 927-0300 or toll-free (800) 808-0300.



Monday, May 31, 2010

Economic Upturn?

Maybe. We're seeing signs.

After a best-ever 2008 we saw about a 25% downturn in 2009. 2010 started off equally bad, maybe even worse. Then, April & May were strong - above our 2008 average. We're cautious, though. The two months were helped by unusually large orders from four customers. So - cautiously optimistic!

Another sign - not necessarily good - component shortages and lead times are increasing rapidly - up to 20 weeks. So far we're able to cope, as most of our parts are available from multiple sources.

Such problems aside, let's hope the improvement continues.

Sunday, May 23, 2010

Application Note

Detect Thermocouple Failure Without Upsetting the Process

One from the archives. Our customer needed to alarm on thermocouple failure without shutting down the process.

Thermocouple instruments commonly include upscale burnout indication. If the thermocouple breaks or fails open-circuit the instrument's output goes high, just as if the temperature had gone out of control. This often is used to insure failsafe failure, shutting the process down and sounding an alarm.

Our customer, a utility, needed an overtemperature shutdown on a monitored water temperature. They also wanted to trip an alarm upon thermocouple failure but without interrupting the process. We were able to suggest a simple dual-trip alarm setup to do this.

Our thermocouple instruments, like most others, offer a downscale burnout option. (Thermcouple failure causes the output to go low instead of high.) Using a dual-trip alarm, we set trip #1 for HI trip and trip #2 for LO. The HI trip, of course, was used to shut the process down on excessive temperature. The LO trip was set below freezing. Its relay would trip when the thermocouple failed but never under normal operation.


Sunday, May 16, 2010

Export Sales

Helping the balance of trade -

Although the majority of our sales are within the US we welcome interntional orders. In the past two weeks we've shipped:
  • 25 more pieces of a custom assembly (4-input load cell amplifier) for our good OEM customer in Sweden. They buy a few hundred per year - we have an open order for 50 more right now.
  • 30 more JH4380W rangeable DC transmitters - specials - with extended temperature ICs to guarantee operation to minus 40 degrees. Although shipped to a US customer, they will be using them in systems exported to Russia. A repeat order - they ordered 54 last year.
  • 6 transmitters to an overseas distributor.
 We're grateful for all orders, foreign or domestic.

Thursday, April 15, 2010

Current Booster

THE BOOSTER!


Well, ok, not that booster!

Another "rush" special - to boost the current drive from a voltage signal. Our customer needed -10 to +10 volts to drive a 50 milliamp load. The voltage output from their control signal could supply only a fraction of that, so they needed an output-equals-input driver or current booster. They called us.


  • Additional needs: "ASAP - yesterday if possible" because they had just discovered the system problem.

  • Very high accuracy for their test application.

We got lucky. Years ago we solved another customer's high-current requirement by designing a custom circuit board. The requirements were different, but we were able to use that board to assemble the required circuit. It so happened that we had three of those boards left. Our customer needed four, but two could wait. We received the order March 22, shipped the first two March 23 and ordered a few more boards from a quick-turnaround service.

Accuracy? We guaranteed +/-3mV on a 20 volt wide span (+/-0.015% of range).

The customer has now asked us to quote on an 8-channel version.

Saturday, February 13, 2010

Two Wire Transmitters

Some People Like

Trimpots!

We recently picked up a new customer who ordered a few of our 2-wire thermocouple transmitters. This customer sells thermocouples and other temperature probes, and the manufacturer they represent also offers transmitters from a well-knows European company.

Why did they buy ours? The European brand is computer-ranged. The end user wanted to be able to adjust calibration without needing a computer set-up. So, they bought our "old fashion analog" fixed range Model JH220 - complete with trimpots!

This is at least the second time this has happened. Another of our customers, a temperature sensor manufacturer, ran into exactly the same objection years ago and regularly offers our transmitters even though they also handle the European brand.

Do you need to change ranges but still like trimpots? Model JH225 (shown) adds switches that let you recalibrate to almost any practical range for thermocouple types J, K and T. (You do need a calibration source.) We also offer similar transmitters for RTD (resistance thermometer) sensors.

Links:
Model JH220, thermocouple 2-wire transmitter, fixed range (factory set)
Model JH225, thermocouple 2-wire transmitter, user-rangeable
Model JH240, RTD (resistance thermometer) 2-wire transmitter, fixed range
Model JH245, RTD 2-wire transmitter, user-rangeable

All 2-Wire Transmitters

Saturday, February 6, 2010

Simple Specials

Standard Product, Nonstandard Connections

Our OEM customer needed a fully compatible replacement for a thermocouple alarm module they once bought from England. Our Model JH1200 plug-in thermcouple alarm filled the bill, except the pin connections were different.

The answer was simple - take our standard product, unsolder the internal wires from the pins and rewire them to be the same as the British product. And, since the the connections to the thermocouple were changed, we also needed to relocate the temperature sensor used for cold junction compensation.

One more step - we made a simple adapter to allow the converted alarm module to plug into our standard production test and burn-in fixtures.

This customer buys only one or a few at a time, but they've become a regular for several years.

Links: Process Alarms
JH1200 Thermocouple Alarm
Custom & Special Signal Conditioners

Thursday, February 4, 2010

Simple Specials

SPECIAL ORDER -

SUM THREE UNEQUAL FLOWS

Flow #1: Full Scale (20mA) = 1.75 MGD (Million Gallons per Day)

Flow #2: Full Scale (20mA) = 22 MGD

Flow #3: Full Scale (20mA) = 1.04 MGD

Module Output: Full Scale (20mA) = 24.79 MGD

Something we do all the time - modify our products to meet out-of-the-ordinary needs. In this case the customer needed to add signals from three flowmeters, each having a different scale factor.

A bit of engineering calculation, followed by the selection of a few precisely-measured input resistors, did the trick.

One piece order. Turn-around time - four days from order entry to shipment.

Sunday, January 31, 2010

Product Spotlight

Two-Wire Transmitter -
Potentiometer Input

Our "sleeper" product - not new and, you would think, not particularly exciting, but people keep finding it and buying it, so we thought we'd feature it.

Pretty simple - takes a potentiometer input and converts it to a 4-20mA two-wire (loop-powered) output. Quite honestly, it was an afterthought when we designed our temperature (RTD and thermocouple) two wire transmitters years ago. Laying out the circuit board so it could also be assembled for potentiometer input was easy, so we included it.

Sells better than we ever expected. Just this month we picked up two new customers for it. The applications can be anything that needs to convert position to an electrical signal. A couple applications - level measurement and boat throttle position. The level measurement application uses a probe with series of resistors and reed switches, activated by a magnetic float.

Friday, January 8, 2010

Can You Help????

Here's a question we can't help with. Can you?

The other day a fellow called to ask if we could build a custom dashboard panel for his car. We've had two similar calls recently - at least one of them was from a man who was converting an older model to electric power. (He wanted it to look as much like the original dashboard as posssible.) All of them had seen from our web site that we can design panels and minisystems.

This is outside our area of expertise. Industrial control panels, yes. Automotive, no. We'd need to know the size, shape, mounting arrangements etc of the car's dashboard and the electronic details of the car's sensors.

I thought I'd post this for our readers. Can you help, or do you know anyone who can?

Sunday, January 3, 2010

Product Spotlight

.
Field Mount Enclosures

In our last posting (December 26,2009) we highlighted our FDT5000 Series field mount transmitters with displays. If you don't need a display you can mount any of our plug-in transmitters and alarms in the two enclosures featured here.




NEMA-4X Rated Enclosure

Splashproof & corrosion resistant, it includes the mating socket. It is normally sold without an opening or conduit connection as the installer usually prefers to determine this detail. If you would like us to provide this please e-mail jhtek@jhtechnology.com or call 941-927-0300 (in the US, toll-free 800-808-0300) us with your requirements.

Part #ENCL-1-8 with 8-pin socket, or ENCL-1-11 with 11-pin socket.
.

Explosion Proof Enclosure



This is a Hubbell-Killark enclosure, modified by adding an 8- or 11-pin socket. UL, CSA and Factory Mutual approvals include Class 1, Div 1 & 2, Groups A, B, C & D when properly installed. A neoprene o-ring assures water-resistance per NEMA 4/IP66. Two 3/4 inch-14 NPT threaded conduit openings are provided.

Part #ENCL-EX1-8 with 8-pin socket, or ENCL-EX1-11 with 11-pin socket.