Anyone have any info on how to get these to switch on. The rear panel has a 25 pin D connector, I guess sense, fail, operate lines etc. Powers on and fans run but no output. Model No MightyMite MMA31 -1/115-230 (5V 200Amp 1000W) TIA JC
On Mon, 22 Aug 2011 10:33:29 -0400, Archon put finger to keyboard and composed:
FWIW, the SuperMite SM24 LH Research PSU of the 1980s had a 9-pin (3x3) Molex connector that incorporated the following signals:
- on/off (input)
- AC power fail (output)
- DC power OK (output)
- "I" monitor (output)
- hi margin
- lo margin
- +sense
- -sense
The on/off pin was switched to ground to shut down the PSU. The fan ran continuously.
To get the SM24 to regulate properly, you needed to connect the sense wires to their respective load points, or jumper them directly to the supply's outputs.
The hi/lo margin pins could be left open.
I'm guessing that the on/off pin would be pulled up to a standby voltage via a resistor.
- Franc Zabkar
-- Please remove one 'i' from my address when replying by email.
Hi Franc,
Thanks for the reply, I don't think I'm going to get far by trial and error. LH research seems to be Pioneer Magnetics, a completely useless website with a very high opinion of themselves and no tech support/documentation at all.
JC
On Wed, 24 Aug 2011 11:11:26 -0400, Archon put finger to keyboard and composed:
You could determine which pins are the sense lines by measuring their resistance (~100 ohms ?) to each of the +5V and Ground outputs.
The on/off pin would probably be sitting at Vstandby (+24V ?)
The AC Power Fail pin may identify itself if you rejumper your AC input plug for 240VAC, assuming your local supply is 110VAC.
- Franc Zabkar
-- Please remove one 'i' from my address when replying by email.
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