Any problem with 16V caps?

[scheffehcs]

Hello, I just got started building pedals earlier this year and at one point early on I ordered a ton of 16V caps. I'm wondering now if there are some pedals that I shouldn't use them in. For example I just built a Phase II and I'm about to build a Paragon - both have charge pumps. Will this be an issue? Are there any other situations where I should avoid using the 16V caps?

Thanks!

 

[Betty Wont]

Yes, that can indeed be an issue with charge pumps. you can get away with 16v caps in a 9v circuit, but any charge pumped areas of the circuit will need more. The general rule of thumb is 2x the circuit voltage. Determine what the voltage output of the charge pump application is in your circuit and go from there.

 

[scheffehcs]

Thanks for responding. Gotcha, I figured it would be something like that. oh and just to specify I was referring only to electrolytic capacitors.

I have a few follow up questions if you don’t mind. Do different charge pumps have different functions, or is controlled by the components that are attached to it? How do you know what a charge pump is doing - reading the spec sheet for the charge pump or is it evident on the circuit schematic? Lastly - for pedals I’ve made with the 16v caps that could be run on 18v, like a Timmy for example, should I be replacing those caps with 35v or 50v caps?

Thanks!

 

[twebb6778]

The function of the charge pump is affected by both the IC and the circuit. For example, MAX1044 is typically used as a voltage doubler, but can also be used as a voltage inverter or divider depending on the circuit.

For pedals running on 18v, 35v caps should be ok. 50v caps will also work, but are going to be larger and may not fit on the pcb.