supply question

[AltecDarpa]

I have this kit from qkits, and have a few questions before I power it up, it says its a split rail supply, does this mean reading for each rail +/- needs to be taken from +/- to ground? a reading from + to - would just be the combination of both rails? is this correct? on the PCB you hook up the lead for the center tap next to where it shows ground after the caps.

[wintermute]

That's correct if you are testing without a load attached, make sure you have some way of safely discharging the caps. Some bleed resistors from +ve to ground and -ve to ground would do the trick. I can't see what voltage the supply is but something in the 2K 3W range might be ok.

The caps will retain charge for a LONG time without some way of discharging and if you short them you could damage them, as well as the possibility of getting a nasty fright or a burn.

Tony.

[AltecDarpa]

I have been using an old lamp with a 60 watt bulb to discharge caps, I just cut the lamp cord and touch the leads to the output of supply/caps, is this ok to do? it drains the caps and seems to work well.

[richie00boy]

Yes that's a very nice way.

[AltecDarpa]

ok, thanks too both of you for your help, I will power up the supply and make sure it measures correctly.

[AltecDarpa]

ok, I just looked at the supply and had another question, lol

when measuring the + and - rails to ground, I assume I measure with the positive probe on the positive rail and negative probe on the ground? and for the negative rail do I place the positive probe on the ground the the negative probe on the negative rail?

[richie00boy]

Yes. If you connect the probes the wrong way you won't hurt anything, just read opposite polarity (assuming a digital meter).

[AltecDarpa]

alright, thanks again

[wintermute]

Hi it will depend on your multimeter! If you have a digital multimeter then you can use the COM (-ve) probe on the ground and the reading will be + or - on the DMM display for +ve and -ve rails.

If you have an analog meter (ie old type with a needle), then you would have to do as you have asked.

Light bulb is the way I discharge PS caps that don't have bleeder resistors in them It is very effective too

Tony.

[AltecDarpa]

the supply tests fine, now I have yet another question, is there anyway to hook this supply up to 2 mono amp boards that both need + and - dc input? the combined voltage of + to - is almost twice the voltage the amp can take, and half would be perfect, soo....

If I understand correctly the negative marked rail gets its positive from the ground, would I just wire the positive of the left channel with the negative of the right channel, then attached them both to the ground on the supply board? or would this result in fire.

If that is not clear I could produce a workable drawing of what I mean in MSpaint.