I'm a noob in electronics. Actually, I'm asking here in Stackoverflow for my physics experiment 🙂
I need a AC power source that has a range of approx. 20V – 250V.
I'm using this source to power an electromagnet that is constructed by using enamel coated copper wire of 0.3mm
I need to be able to generate sine waves with frequencies of approximately 100 hz – 3000 hz.
I found that normal function generators do not have enough voltage & power to support my experimental setup. Slidac was also something I considered, but since it transforms the voltage from the input source of 220V, the output current becomes too high in cases of low output voltages.
Thanks a lot in advance.
Best Answer
Modern professional audio power amplifiers are available for rent from some music stores and most PA System rental companies. These are available with maximum output voltage depending on how much power the amplifier has.
For example, a Crest Audio CA-1200 is rated to provide 2400 Watts RMS into an 8 Ohm load (bridged output). That works out to 300 Vac RMS. That is: the output voltage is adjustable from zero to 300 Vac at max power.
There are many other similar amplifiers from a variety of manufacturers available - I mention this one only because I have used it in the past.
I'm suggesting an amplifier like this because they are usually readily available from rental houses for a low-cost daily or weekly or monthly rental fee.
Note that in order to achieve this output voltage, you have to switch the amplifier to what is called "Bridge Mode". This is where the output signal comes from the two HOT output terminals on the amplifier. One channel provides up to 150 Vac, the other channel provides the exact same signal except 180 degrees out of phase. The sum of those voltages gives you the 300 Vac available.
The consequence of this is that both of the output terminals are live with respect to ground. Your question doesn't indicate whether this is a problem or not. It usually isn't but you need to be aware of it.