I have the following problem : I have a triple output DC power supply (Agilent E3631) : +6V, +25V and -25V. I need to construct something that will enable me to have -12V to +12V across two terminals. The current requirement is about 7 A (driving a heavy motor).
What would be the best way to go achieve this? Any suggestions are greatly appreciated.
One option is to create so called "virtual ground" ..
If your power supply can deliver 25V @ 7A then:
you will need two power transitors (1xNPN and 1xPNP, Darlingtons) mounted on a heatsink, and here is explenation on how it can be done: https://tangentsoft.net/elec/vgrounds.html
for higher currents reduce the emitter resistors (R3 and R4) to 0.1Ω or less ..
is this a DC motor? i have had similar problem before and i just put 24V across DC motor terminal - though it was only a 12V motor. it spins twice as fast.
IanP : Thanks. That might just be what I need. I'll check it out.
Mr. Cool: Yes, it's a DC motor. The issue is that I need to alternate the direction of rotation at a certain frequency. Since I can program the power supply, I thought the easiest way is if I could figure out a bipolar power mechanism.
Optionally, if there was something akin to a "high-voltage multiplexer", where I could select which terminal output to select (-ve or +ve).
For changing direction you can employ the H-Bridge configuration ..
Here is an example: **broken link removed**
In this circuit, the supply voltage can be 24V (and more, with Z1 removed) ..