I've got a piece of electronics on my bench that is normally powered by
3 C batteries, wired in series and thus producing about 4.5 Volts. I wanted to power this device with a bench power supply just so I don't drain the batteries while I'm experimenting with it for hours.But it won't work with the DC power supply -- it's the weirdest thing. With the batteries, the device (a child's toy) chatters away at full power, but if I disconnect the batteries and wire in the DC PS in their place, it runs veeeeery slowly, if at all.
I feel like it's the 18th century and I'm missing the right amount of "essence" or "ether" or "humours" or something :)
I've checked and double checked the voltage including polarity. I've tried running at depressed voltage (e.g. 3-4V). The power supply should be able to provide far more current than the batteries, and at a low output impedance. I have two power supplies, one a fancy bench model and the other a wall wart, and it does the same thing with both. Only with the magic batteries will it work properly.
Perhaps related, in the device at the + side of the battery back is an orange disc which appears to be a ceramic capacitor wired in SERIES, but I don't see how it could be given that this is a DC device. I've been attaching the DC PS on the battery side of this disc, in order to provide DC power to the circuit just like the batteries. I don't know if this is relevant.
Any ideas?