USB charger to power relays

[bbbing1]

Hi there

I'm trying to explore options to power the relay on my old Sloclone.

Its currently running off the AC heater filaments in generating some noise.

I'm considering using a USB phone charger running off the main power supply to drive the two 5V relays.

Has any body tried this and will this quieten the amp?

Thanks
Bing

[dorrisant]

Those chargers usually have a 5v switch mode power supply inside. I use them quite frequently without much problem.

[pompeiisneaks]

I would think the only thing to be careful of with SMPS is that the switching can create a lot of noise, so make sure you keep it far away from the signal path... unless that signal noise is so high it's out of the frequency range of the audio path? Not sure... heh.

~Phil

[xtian]

Lou implemented a switching PSU for the switching circuit on the HRD->ODS PCBs we've been building. Noise proved to be a non issue.

[pompeiisneaks]

yeah as I just even commented on the end, I started thinking the switching noise is in the extremely high frequency range, probably not audible at all. I think it's a design consideration for wifi/cellular etc. Ignore me It was early, not enough coffee yet

~Phil

[bbbing1]

Thanks for the replies. Will give it a try. I have plenty of chargers lying around. Can potentially save $$$, space and not worry about another transformer and additional circuits.

[dorrisant]

If you're careful, you can reuse the enclosure after removing the plug leads.

[TUBEDUDE]

Those switching supplies usually get noisy when loaded down hard, which will never be an issue with driving relays.