9v Adaptor, How many Pedals??

[Frankgb]

Hi,

I'm going to build a rectified/filtered 9v supply to run some pedals with, I just wondered what is a rough rule of thumb for current consumption, or the capacity of a normal 9v battery?

I have a Boss PSA-240 Adaptor rated at 200mA DC, and a Sega Mega Drive Adaptor trated at 850mA DC.

Thanks for any help!!!

Frank Berend

[SnooP_Wiggles]

Hmm a rule of thumb. 20ma a pedal?
have a look here instead for actual ratings of every boss pedal
http://www.cioks.com/assets/CURRENT%20CONSUMPTION%20TABLE.pdf

its got other brands as well

[Travis]

If you're not into some crazy stuff, 200 mA should be more than enough for all of your analog pedals.  

If you use some digital equipment, you may need to use that 850mA.  

Is the Sega regulated?  If not, remember that the specs are for 9V when providing 850mA of current.  At lesser loads, the voltage will be higher; much, much higher for that 850mA PS (probably around 20V).  You will likely want to regulate your PS in addition to rectifying/filtering.

The good news is this:  regulators are cheap and easy to use.  An LM7809 or the adjustable LM317T should cover your needs.  The larger versions can supply 1 amp with heatsinking.

My general rule of thumb is for about 5mA for an off effect, and about 15-20mA on.  The LED is far and away the biggest current hog.  This balances out as my homebuilds tend to use significantly less current than my store-bought pedals.  Digital effects can use far more, going into the hundreds of mA.