Power supply noob info

[Luke51411]

I am a noob to powering effects and I want to eventually be able to build power supplies and pedals that require more voltage. At this point anything beyond 9v is foreign territory. Where is the best place to start learning about things such as voltage regulators, charge pumps, power supplies and their uses, limitations, and design? I'd like to work my way up to eventually be able to build tube amps though that is a LOOONNG ways off.

[garcho]

Check out GEO FX and Music From Outer Space websites for charge pump and bipolar low voltage ideas that won't kill you. High voltage you learn in person from a human with years of experience, NO exception.

[Luke51411]

Thank you, yeah I'm definitely looking for projects that won't kill me . What voltage range would be considered "safe" to work within? I just don't want to always be limited to the constraints of a 9v power supply but I want to make sure I know all the details before I jump into anything else.

[garcho]

This forum's search engine isn't the best, try something like Duck Duck Go.

[Seljer]

Thank you, yeah I'm definitely looking for projects that won't kill me . What voltage range would be considered "safe" to work within? I just don't want to always be limited to the constraints of a 9v power supply but I want to make sure I know all the details before I jump into anything else.

The scary stuff starts when you have to do 110V/230V AC wiring where like Garcho mentions, learn about proper ways of doing it safely!
You can get around this issue temporarily by using an AC wallwart, which leaves you to just design the rectifier and filtering (and voltage regulation if you wish).

On the DC voltage side, everything up to about 50V is 'safe' (albeit rather tingly). Above that you should be performing strict procedures of unplugging and discharing the power capacitors before poking around in the circuit if you don't want any nasty surprises 


The Geofex power supply article is covers the basics of your simple diodes+capacitor power supplies. In an amp you'll find the same arrangement, just with higher voltage ratings on all of the components.
http://www.geofex.com/Article_Folders/Power-supplies/powersup.htm

[PRR]

Most safety regulations allow anything under 25V as "safe". Pop the cover on your thermostat, there's 24V right there on the screws. 25V across typical skin resistance does not flow enough current to do significant harm. (Note however that cats can be seriously injured or killed by even lower voltage.)

European rules tend to discourage 48V finger-contact, though 48V microphone Phantom power is tolerated (because it should only be used by Professionals, and because mike connectors are fairly finger-safe).

Another class in US wiring allows loose construction on 70V circuits with limited power; mainly large speaker systems. Again there is the notion that only Professionals will be poking at the wires and screws.

Edison picked 100V for his early electric-light systems because he had no good insulation and he found fewer dead workers around 100V gear than around higher-voltage gear.

As Simon says--- aside from personal shock, there is a FIRE issue. Small (10 Watts) transformers won't pass big power even when woefully mis-connected, and fires rarely happen. However the 120V 20A (230V 13A) from the wall can deliver thousands of Watts for plenty long enough to start fires on the bench or inside the walls, sling molten copper, even blind you. Like handling loaded guns or poison snakes, it needs a higher level of training and caution.