Hi there,
Last year I was trying to repair a laser machine that required +12v and -12v to control the servos for the mirrors. I did not fix the power supply but was trying to test it using an ATX power supply. The + side worked a bit but the negative did not, I tested the current draw through the meter on the +ve side and it was around 3 amp and so the -ve side could not pull enough since the ATX was only rated at 0.8 amp and tested at 1 amp through the meter.
Last night while building a bench power supply I had an idea and after some reading thought it should work.
From reading it is saying 0v does not exist, the multimeter is just measuring the potential difference. So I made a circuit (see pics). Which works when measuring the voltages. The +ve of the buck becomes the 0v in respect of the +12v and -12v.
Please advise if there is anything wrong with this circuit for generating a -ve rail!
If this is right I will make my bench power supply so that it can provide -ve voltages like this for future testing!
I can alter the values on the Boost and the Buck so it would equal 12v each. I just wrote down what it was set on at the moment.
I know you can also create a negative rail with a transformer with 3 taps as well.
Now how will the current draw be? Will it be shared if the voltages are equal so the currant of the boost split if I do not limit the current on the buck.
What would happen with the current draw if the voltages were set un-equally?
Can the buck be damaged if I only run something off the positive side in that circuit so the + of the buck is being used as the negative but is sinking the current???
Many thanks!
Last year I was trying to repair a laser machine that required +12v and -12v to control the servos for the mirrors. I did not fix the power supply but was trying to test it using an ATX power supply. The + side worked a bit but the negative did not, I tested the current draw through the meter on the +ve side and it was around 3 amp and so the -ve side could not pull enough since the ATX was only rated at 0.8 amp and tested at 1 amp through the meter.
Last night while building a bench power supply I had an idea and after some reading thought it should work.
From reading it is saying 0v does not exist, the multimeter is just measuring the potential difference. So I made a circuit (see pics). Which works when measuring the voltages. The +ve of the buck becomes the 0v in respect of the +12v and -12v.
Please advise if there is anything wrong with this circuit for generating a -ve rail!
If this is right I will make my bench power supply so that it can provide -ve voltages like this for future testing!
I can alter the values on the Boost and the Buck so it would equal 12v each. I just wrote down what it was set on at the moment.
I know you can also create a negative rail with a transformer with 3 taps as well.
Now how will the current draw be? Will it be shared if the voltages are equal so the currant of the boost split if I do not limit the current on the buck.
What would happen with the current draw if the voltages were set un-equally?
Can the buck be damaged if I only run something off the positive side in that circuit so the + of the buck is being used as the negative but is sinking the current???
Many thanks!
Comment