Thurlby Thandar RSComponents Bench Power Supply
I have an old 30V 2A bench power supply badged RS Components Code 610-461
which was made by Thurlby, now Thurlby Thandar Instruments (tti). The current meter shows OFL which I found out means overload. It has linear regulation using a couple of 3055s and looks similar to the EL series on the tti UK website http://www.tti.co.uk/products-tti/psu/psu-bench.htm Internally it is very similar to an RS Components 610-477 although that is a dual 30V 1A power supply. I have given it a quick check and can't see anything obviously wrong. Does anyone have a schematic or any other info that might help me repair it? Thanks John |
Thurlby Thandar RSComponents Bench Power Supply
johnwass wrote:
I have an old 30V 2A bench power supply badged RS Components Code 610-461 which was made by Thurlby, now Thurlby Thandar Instruments (tti). The current meter shows OFL which I found out means overload. On my Thurlby's (considerably older though), OFL means you have the current limit control set fully clockwise equating to the 'no current limit' setting (let me smoke & catch fire first....). This when the power out switch is off. Try turning the control down? Could be the control itself is faulty if no change. -- Adrian C |
Thurlby Thandar RSComponents Bench Power Supply
Adrian
Thanks. However, current limit control setting makes no difference. Always shows OFL. Thought it was unlikely to be the control but I will try swapping it for a different one to see if it makes any difference. John "Adrian C" wrote in message ... johnwass wrote: I have an old 30V 2A bench power supply badged RS Components Code 610-461 which was made by Thurlby, now Thurlby Thandar Instruments (tti). The current meter shows OFL which I found out means overload. On my Thurlby's (considerably older though), OFL means you have the current limit control set fully clockwise equating to the 'no current limit' setting (let me smoke & catch fire first....). This when the power out switch is off. Try turning the control down? Could be the control itself is faulty if no change. -- Adrian C |
Thurlby Thandar RSComponents Bench Power Supply
johnwass wrote:
Adrian Thanks. However, current limit control setting makes no difference. Always shows OFL. Thought it was unlikely to be the control but I will try swapping it for a different one to see if it makes any difference. John "Adrian C" wrote in message ... johnwass wrote: I have an old 30V 2A bench power supply badged RS Components Code 610-461 which was made by Thurlby, now Thurlby Thandar Instruments (tti). The current meter shows OFL which I found out means overload. On my Thurlby's (considerably older though), OFL means you have the current limit control set fully clockwise equating to the 'no current limit' setting (let me smoke & catch fire first....). This when the power out switch is off. Try turning the control down? Could be the control itself is faulty if no change. -- Adrian C That happened to mine (Thandar TS3021S) There was a diode soldered directly across the output terminals which was shorted - I suspect someone had use it to charge a gelcell and connected it up the wrong polarity. Ron(UK) |
Thurlby Thandar RSComponents Bench Power Supply
Current pot resistance checks out. All 3 diodes connected between outputs
are fine. John "Ron(UK)" wrote in message ... johnwass wrote: Adrian Thanks. However, current limit control setting makes no difference. Always shows OFL. Thought it was unlikely to be the control but I will try swapping it for a different one to see if it makes any difference. John "Adrian C" wrote in message ... johnwass wrote: I have an old 30V 2A bench power supply badged RS Components Code 610-461 which was made by Thurlby, now Thurlby Thandar Instruments (tti). The current meter shows OFL which I found out means overload. On my Thurlby's (considerably older though), OFL means you have the current limit control set fully clockwise equating to the 'no current limit' setting (let me smoke & catch fire first....). This when the power out switch is off. Try turning the control down? Could be the control itself is faulty if no change. -- Adrian C That happened to mine (Thandar TS3021S) There was a diode soldered directly across the output terminals which was shorted - I suspect someone had use it to charge a gelcell and connected it up the wrong polarity. Ron(UK) |
Thurlby Thandar RSComponents Bench Power Supply
johnwass wrote:
Current pot resistance checks out. All 3 diodes connected between outputs are fine. John OK. If your assertion that the OFL display means overload is correct, I'd take that to mean that its an indication from the display modules built-in ADC that there is excess voltage at it's input compared with it's specifications for full scale 'deflection'. Can you see what part they used, find a datasheet and trace the input pin(s). Then stick a meter there, attach a load and see if on varying the output voltage if there is anything sensible changing for these inputs. I'm guessing all of the circuitry still is plain discrete analogue driven (compared with my old PL154) and you might find the culprit through simple fault finding. If it is a silicon jungle chip maybe not. Though a manual has to be found from somewhere ... -- Adrian C |
Thurlby Thandar RSComponents Bench Power Supply
On Fri, 26 Sep 2008 22:56:36 +0100, "johnwass"
put finger to keyboard and composed: I have an old 30V 2A bench power supply badged RS Components Code 610-461 which was made by Thurlby, now Thurlby Thandar Instruments (tti). The current meter shows OFL which I found out means overload. It has linear regulation using a couple of 3055s and looks similar to the EL series on the tti UK website http://www.tti.co.uk/products-tti/psu/psu-bench.htm Internally it is very similar to an RS Components 610-477 although that is a dual 30V 1A power supply. I have given it a quick check and can't see anything obviously wrong. Does anyone have a schematic or any other info that might help me repair it? Thanks John If your PSU senses the current via a low ohms series resistor, then an open resistor may produce the observed symptom. In any case it may be a good place to start troubleshooting. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
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