programming lambda lqd power supplies? - Page 1
Forum section: electronics / testgear

author: ftransform
author_rank: Frequent Contributor
timestamp: June 01, 2013, 11:03:47 am
content: Does anyone know how to program the LQD lambda power supplies? I found a manual online, which says to refer to a wiring diagram, which is not in the manual...It has screw terminals on the back labeled:Po+s+dcRp-dc-sATgroundS+ and DC+ are linked (sense and positive terminal)S- and DC- are linked (sense and negative terminal)Ground is linked to chassis groundNo idea what RP, Po and AT are.It has the ability to be programmed by a voltage source and a resistor, I would like to use a voltage source.http://drco.pairserver.com/manuals/lam2.PDFmanual with no pictures.

author: ftransform
author_rank: Frequent Contributor
timestamp: June 01, 2013, 06:31:27 pm
content: I tried connecting an agilent power supply to the sense and positive pin (as suggested by another lambda manual) and this did not work.I poked the Ro and v- with an agilent power supply and a capacitor exploded. Note to self: dont plug random stuff in.capacitor was replaced and the transistor is ok but no new clues on programmingI think PO might have something to do with sequencing units, like in parallel.oh, that was easy, you just connect +V to Rp and V- to V-.I figured Rp had to do with the resistor programming but it works fine really. groovy.now to figure out current programming... hmmm......It does however seem to have a problem, if you adjust the reference voltage too quickly the thing gets stuck.Does anyone have any insight? Is that a limitation, I.E. you cant change the programming voltage too quick? should the sense pins be connected in this case?Also, there is a voltage difference between the programming supply and the output supply (100mV at 20V)Also, when a current is drawn the programming supply needs to supply roughly 1/3 of the current, for 180mA the programming supply needed to supply 60mA.That does not seem right to me....I must be missing somethingah ha, you need to cut the negative sense terminal off from the circuit and leave the positive sense terminal connected.idk if i want to fuck with the current source

author: JimmyMz
author_rank: Regular Contributor
timestamp: June 01, 2013, 07:50:33 pm
content: I know you are getting along better than when you started, but I'd like to point out for others that Rp is typically indicative of Parallel Resistor. Good luck with the other issues you are currently tackling. I unfortunately don't own a Lambda PS.

author: ftransform
author_rank: Frequent Contributor
timestamp: June 01, 2013, 07:56:21 pm
content: Quote from: JimmyMz on June 01, 2013, 07:50:33 pmit works now, connected to Rp with the V- sense cut off and the +V connected to Vsense+.There is a slight offset (40mV) still. I may be misusing it but it seems to work. At this point I can drive 20V @ 180mA with 20V at <10 mA.I might be misusing the resistor hookup I suppose..... But I am scared to try more things because of the smoke !what in the hell do AT and PO stand for though? I assume RP means either resistor program or remote program.

author: JimmyMz
author_rank: Regular Contributor
timestamp: June 01, 2013, 08:27:53 pm
content: Maybe "Po" isParallelOperation and "Ta" isAmbientTemperature

author: ftransform
author_rank: Frequent Contributor
timestamp: June 01, 2013, 11:56:13 pm
content: Quote from: JimmyMz on June 01, 2013, 08:27:53 pmooo perhaps it has a thermistor in it, but this is not mentioned in the manual.edit: it does have a themrostat shutdown mode but its not mentioned in manual it can be accessed externally.

author: ftransform
author_rank: Frequent Contributor
timestamp: June 02, 2013, 05:23:30 am
content: I dont think its a temperature pin, it seems to behave rather randomly. At first it does look like a temperature output, but it changes too quickly with programming voltage.I left it connected to a load and it slowly rised to 11v, but then when I came back into the room (load was still running) it dropped to 9V. The room temperature did not really change much..perhaps it cant be used in conjunction with voltage programming or there is some kind of fault in the circuit, because it does slowly rise when there is a load on it.i might take this apart and trace it to something but I will wait for responses because that's alot of work.yay its broke

author: ftransform
author_rank: Frequent Contributor
timestamp: June 04, 2013, 09:13:14 am
content: 30$ of repairs later.......am I gonna have to buy a manual for this thing?

author: ftransform
author_rank: Frequent Contributor
timestamp: June 10, 2013, 01:04:57 pm
content: spare parts should be here soon bumpUsing the sense + as the input and the neg as ground (for another supply) seemed to work for a while, but there was a mismatch (0.3 volts between control supply and output), but eventually this broke the controller IC.

author: rsaxvc
author_rank: Contributor
timestamp: July 03, 2024, 12:01:22 am
content: Appologies for the necro-bump, but I've got the same wiring quesions for my pair of LK-351. However, I also found the instruction manual for Lambda LDS-X series, which use the same terminal names, and I'm hoping are wired similarly. Attached are the LDS series interconnection diagrams I found.