need schematic or pinout for Ungar 9900 soldering station. Wanna use it on a Pace Iron.

I have a Pace tweezer soldering iron. 21V I have an Ungar 9900AS power unit. 24V I'd like to mate them. The 6-pin round connector plugs in...I'm afraid to turn it on. I found some pinout info on Pace systems, but nothing on the Ungar.

A schematic or pinout info would save me reverse engineering the thing.

Thanks, mike

Reply to
mike
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I haven't had a 9900 series controller, but I do have a few 4000 series desoldering stations, and there should be 3 conductors from the plug.

By taking the cover off the unit, you should be able to determine which connector pin is for earth ground (the heater barrel & tip), and the 2 pins for the heater. I'm fairly certain that there are not any other pins used (no temp feedback device).. I've only seen 3 conductors used for Ungar handpieces/irons.

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WB 
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Reply to
Wild_Bill

Typical Ungar variable temp iron has six-pin connector with typically 5 used. Turns out that the temp sensor resistance is incompatible. Without a schematic, it's just too much work to redesign it.

Reply to
mike

I've owned at least 4 models of different series of Ungar varaible temperature units (from the 1970s to 2000) but also repaired other models, and all of 'em only used 3 conductors for the handpiece heater.

The units I've had that were combination soldering/desoldering units had an extra (1 or 2) conductors for the vacuum circuit.

If your station doesn't have a vacuum circuit (not mentioned previously), the heater was likely only 2 wires plus an earth ground. So.. no, not really typical for Ungar units to use 5 conductors for a soldering iron.

If the 9900 unit did use 5 wires for just a soldering iron, it may have been the only Ungar station that did. I don't know why there would be more than 3 conductors for the soldering iron that went with that unit, unless it has a digital temperature display.

You could connect two small 12V lamps in series to find the heater pins.

I haven't seen a temp sensor used in Ungar soldering irons, and I don't remember seeing any in my Pace tweezers either.

I guess you could always use a variac and a 24V transformer, or find a lamp dimmer for 24V.

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Cheers, 
WB 
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Reply to
Wild_Bill

After seeing a picture of the 9900 unit, I remember having a couple of those.. that are in a box downstairs.

I don't have my notes handy, but all of the Ungar soldering irons and desoldering handpieces that I've seen do not operate the heaters with any sensor/feedback device. The "control" circuits are duty cycle types, not tightly regulated feedback types.

That's why the 9900 series station has a switch for using different wattage irons.. to more closely match the duty-on cycle to the different sized heaters. These duty cycle type circuits allow the temperature to be varied/adjusted, but it's not regulated (the way some other brands of soldering units operate).

I don't recall the Pace tweezers having any feedback sensor either, but if it does, it doesn't have to be used to adjust the heater.. again only 3 conductors needed.

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Cheers, 
WB 
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Reply to
Wild_Bill

Can't speak for yours, but my Ungar 9900AS uses two wires for the heater, two for the temperature sensor and a safety ground. As does the Pace SensaTemp II tweezer. Problem is that the Pace us 100 ohm sensor. The Ungar changes duty factor over the range from about

10K to 5K, so completely different sensor technology.

If I could find a schematic for the Ungar, I'd hack it to work with the Pace. Just not sufficiently motivated to reverse engineer the whole thing.

Reply to
mike

If you take the plug apart on the Ungar soldering iron cable (not fun), you'll see there is a mini variable resistor inside the plug.. no sensor used for the iron, in case I forgot to mention that.

The variable resistor is used to set/match the iron temp to the chart supplied with the soldering station (so all the models have some consistency when set to lowest to highest temp settings).

If you remove the leads to the soldering iron and put the Pace heater(s) and ground leads in the same place, the Ungar station will provide adjustable temperature for the Pace tweezers.

This isn't complex.. essentially the same as a light bulb circuit.

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Cheers, 
WB 
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Reply to
Wild_Bill

Very interesting.

9900 AS Anti-Static Electronic Soldering System UTCUTC UTC SERIESSERIES SERIES SOLDERING SYSTEMS This premium, ESD-safe, modular system meets the full range of electronic soldering applications by means of four 24V-AC quick-connect micro and macro soldering irons. Electronically controlled, variable temperature. System meets military specifications: DOD-STD-2000- 1B, WS-6536E and MIL-S-45734E. Temperature range 450 o F to 850 o F. Dimensions 3.33"H x 3.80" W x 7.00"D weight 3 lbs. 120V-AC, 6 Hz., 3-wire grounded. UL Listed. Two year limited warranty on power base.

Temperature variation less than ++ +10 oF ______________________________________________________

I don't have the ungar iron, just the power unit, but I remain skeptical.

So, they adjust the power, not the temperature...but the dial is calibrated in temperature and spec'd within 10 F.

What I did was put a variable resistor on the sense pins. The duty factor of the power source was a strong function of the external resistor and only minimally affected by the setting of the temperature slider. I can imagine that there's a calibration pot that normalizes the variation in sensor resistance between units.

It's hard to imagine that they have all that circuitry to implement a light dimmer.

The pace units actually measure temperature, so it stays constant under varying loads. Weller EC3001 works the same way. Draws about 27W cold and ~3W at temperature, pretty much independent of temperature setting.

Reply to
mike

I located some notes on Ungar units, and the 6-pin connector.

I didn't write down what the actual connector pin numbers were, but can describe them, compared to a clock face.

With the key notch at 12:00, there are 5 pins surrounding one center pin.

The 2 pins closest to the key (10:00 and 2:00) are for the variable resistor located in the plug body of the handpiece.. I didn't write down a value, but sketchy memory leads me to believe the value is under 25k ohm (could be much lower).

The next pins at (4:00 and 8:00) are the heater pins.. either lead to either pin, wire colors are likely to be black & white.

The next pin (6:00) is the handpiece earth ground pin (wire color is likely to be green).

The center pin isn't used for soldering irons.. it's for the pump switch in desoldering handpieces (or to actuate vacuum flow in units that don't have internal pumps).. although some designs utilize a foot switch to activate the vacuum source.

In the majority of temperature "controlled" soldering/desoldering irons I've seen which are the duty-cycle type of controllers (not sensor feedback from the handpiece), the common method of wiring the handpiece is with a mini variable compensation resistor located in the connector plug at the end of the handpiece or adjustable internal compensation pots in the base unit.

The compensation adjustments were provided to allow matching of the tip temperature range (measured with external equipment) to be adjusted to match the temperature divisions (or temp chart) of the temp adjustment setting controls to match approximately. All of the duty-cycle units I've seen have only 3 cable leads for the heater.. 2 voltage and 1 earth ground.. this goes back to when heaters were commonly 120VAC and (simple diac/triac duty cycle) continued up to the more recent 24V designs (isolated and ESD safe versions). Ungar/Weller, Pace, Edsyn and others have all used this design for various models. The connectors and pinouts change, but generally the irons are interchangeable as long as the voltage is within a reasonable range.

In many production assembly line scenarios, the soldering temperatures needed to routinely be checked/adjusted (calibrated) to make sure that the circuit board assembly temps were within a specified range (certifications for contract work, not China assembly methods). Some units have mechanical limiters or locks to prevent the assembly line operator from increasing the tip temps.

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WB 
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Reply to
Wild_Bill

Thanks for the info. The pinout is consistent with my experiments. Sure wish I had the handpiece to look at.

My experience has been opposite yours. My Weller EC3001 has active temperature feedback. If you stick the tip on a cold surface, the heater power goes up. Same for all my PACE handpieces with the 6-pin connectors.

I have some very early 120VAC PACE desoldering handpieces that are controlled power instead of controlled temperature and run off a "light dimmer" in the base unit without temperature feedback.

The Weller 3-pin connector units like the TC201/TC202 have constant heater power that's interrupted by the "magnastat" attached to the tip reaching its curie temperature. It's a bang-bang control system with relatively long on/off times.

Reply to
mike

You didn't say whether you looked inside the Pace tweezer plug, but if you're going to relocate the heater wires you'll probably end up doing that anyway.

I'm quite confident that you will find only 3 wires going to the handpiece, as mentioned before.

If you stick the hot tip of any of the irons I was speaking of earlier onto a cold surface, the LED will change from briefly coming on (idling), to come on steady.. and yet, there are NO sensor leads going to the handpiece (only because there is NO SENSOR).

The same LED action is seen when the adjustable temp control is turned up/increased from a previously lower operating temp.. when the higher temp is reached, the LED returns to briefly coming on (idling again).

I obviously don't need to say this, but.. hey, don't take my word for it. Buy a used Ungar soldering iron handpiece with the same 6-pin connector on eBag and open the connector. It doesn't even need to be a working iron.. doesn't even need a heater, so it should be possible to find one cheap.

I'm sure I have several extra handpieces, but don't know where to look for them.

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Cheers, 
WB 
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Reply to
Wild_Bill

I was gonna modify the socket. I have other places to plug the iron.

Well...hate to shatter your confidence. The info is here:

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it includes a schematic showing the sensor.

Here's the troubleshooting chart for the PACE TT-65 handpiece: Was a PDF chart that got copied as text, but you can see the

4 headers: SYMPTOM CHECKOUT PROCEDURE CAUSE SOLUTION No heat Check resistance - Pin 2 to Pin 5. Resistance should be 10 ohms. If not - -Open Heater

______________Here's the relevant part Handpiece overheating Check resistance - Pin 3 to Pin 6. Resistance should be 110 ohms. If circuit reads less than 105 ohms - -Shorted Sensor ____________End of relevant part.

I believe that you have experience that leads you to a conclusion that is incorrect for the systems I have. Your conclusion seems to be contrary to all my experience. I fail to understand how power input can change with heat load without sensing something.

I know of three ways in use to have temperature control with two active wires (plus safety/static ground). I have used irons using all three methods.

1)put ALL the electronic controls in the handpiece. 2)the weller magnastat that uses a thermally activated switch in the tip. 3)the Metcal system that pumps RF down the cable and uses a property of material in the head to absorb the RF and heat only when below the transition temperature of the tip.

This article describes various systems.

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I won't, because I haven't heard a rational explanation. Can you describe the mechanism that allows the power input to change based on heat flow without sensing something. Finding a calibration pot in the plug doesn't demonstrate that a sensor does not exist.

Buy a used Ungar soldering iron handpiece with the same 6-pin

You don't need an extra one. Just unplug one and take a meter to it. The sensor in my Weller EC1301 sensor measures 27 ohms cold and about

43 ohms at 700F. The only adjustable power supply that I own with the UNGAR name is the aforementioned 9900AS. It has WAY MORE circuitry than would be required for open-loop power control (light dimmer style). The number and type of integrated circuits is consistent with the schematics for the PACE temperature control systems. Not having a handpiece or schematic, I can't prove it. I can only demonstrate that the power out is dependent on the value of a resistor plugged into the socket...assumed to be the sensor. It appears that the type of sensor varies much more with temperature (in the 5K to 10K region) than the sensor used by the PACE or Weller EC series.

Are we having fun yet?

Reply to
mike

Greetings Bill, If the LED comes on when the tip is cooled, and the LED being on means that the iron is being powered, then the control must be sensing that the tip has cooled, of course. If there is no separate sensor in the tip then this must mean that the base unit somehow senses then cooling tip. Couldn't this be done by measuring the resistance of the heater? Eric

Reply to
etpm

That'd be my guess, Eric.. that the control circuit is capable of monitoring the resistance of the heater. The circuits are much more sophisticated than just a diac/triac dimmer in the 24V units.

There is likely to be a method of monitoring the resistance (or current?) of the heater. I dunno what the coeficient properties of ceramic heaters are, but it's likely that the resistance of the heater changes as the temp does (as seen in lamp filaments, for example).

Some sort of differential circuit that causes a balance shift, to be made when the temperature control is increased, otherwise just matching the applied power to the setting of the temp control setting at a duty cycle, in effect, idling until a significant change in heater resistance is detected.

It's been years since I've seen schematics for the Ungar controller circuits, and I may not have any of them now.

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Cheers, 
WB 
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Reply to
Wild_Bill

Well it appears that you're correct about the Pace tweezers having a sensor.

That could be significant if you were wanting to use an Ungar handpiece on a Pace controller.. but you're not. The sensor doesn't prevent the operation of the heaters in the Pace handpiece. My apologies if I forgot to mention that heaters only require 3 wires.. and one is for earth ground.

Finding only 3 conductors in the Ungar handpiece and no sensor leads, as I've done, demonstrates to me that there is NO SENSOR in the Ungar handpieces (proof enuff for me).

Buy a used Ungar handpiece if you need proof. Schematics aren't easy to find.. the last one I got was from an Ungar distribution manager who had access to obsolete equipment literature, and that was maybe 7 years ago. Or, buy a Pace controller.. but you already knew that was an option.

You didn't initially state that you wanted a rational explanation of how the Ungar controller operates, but my suggestion would've been to call Weller/Cooper or whoever owns what's left of Ungar, and ask.

If I were going to use the Pace tweezers with the Ungar controller, I'd connect the 3 heater leads, and experiment with a couple of values of variable resistors at the "not sensor" compensation resistor pins pointed out earlier. If the controller (any controller) doesn't output a significantly greater voltage than 24V, it's not going to destroy the tweezers.

It may be worthwhile to modify the plug for the tweezers to match the Ungar connector in the event that you may want to use an Ungar handpiece in the future.

It's likely that the value of the compensation resistor will be different from the ones associated with the Ungar soldering irons, because the tweezer heaters are different (2 heaters paralleled). The performance of the Pace tweezers may not match the original performance specifications of the Ungar station with the recommended Ungar soldering irons, but it should have a fairly stable adjustable temperature when an appropriate value for the compensation resistor is determined.

There were some high wattage irons available for the Ungar 4024 unit, for example, but I don't know if the 9900 controllers are similar.

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Cheers, 
WB 
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Reply to
Wild_Bill

Wild_Bill formulerede Wednesday:

I'm not arguing if the particular soldering iron has a sensor or not.

But, as resistance (often) is inversely related to temperature, wouldn't it be possible to measure the current and voltage, and use this to keep the temperature (somewhat) constant?

Leif

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Reply to
Leif Neland

Følgende er skrevet af Leif Neland:

Note to self: You may compose answers as you read along the message thread, but don't send until all messages are read, to avoid duplicates :-)

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Reply to
Leif Neland

Yep, Leif.. I believe the controller circuit is monitoring certain parameters related to the resistance change of the ceramic heater element since the temperature control is (somewhat) maintained without the use of a sensor in the handpiece providing feedback related to tip temperature.

It's bee a long time since I've seen the schematics of the Ungar 4024 and similar units, and have no recall of the ICs used in the circuits.

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Cheers, 
WB 
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Reply to
Wild_Bill

i have pinout of the output plug (no internal schemo), will soon post it.....

Reply to
hapticz

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I repaired a hair straightener the other day (thermal fuse) that used c urrent monitoring to set the tempt of the ceramic heating element.. So it is done and appears to be quite accurate.

Reply to
sparky

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