Best place to place bleeder resistor in a power supply?

[G]

Originally posted by cliffhiker
As long as the primary will sustain the voltage... here's a great way to bleed it quickly that I've used on low voltage supplies

http://www.reed-electronics.com/ednm...es/70501di.pdf

or

http://www.reed-electronics.com/ednm...bestofdi_power

A profoundly clever, yet simple, idea! Thank you.

[jueic]

Originally posted by Eli Duttman
Gavin,

The purpose of bleeder resistors in PSUs employing cap. I/P filters is to discharge the caps. when the unit is powered down.

Other than dischaging the caps, the bleeder resistors main purpose should be providing the minimum load current for chokes.

Minimum Current= 2*1.414*Vin /6Pi *pi *f *L

Choke can not operate correctly if the current falls below the min value.

[cliffhiker]

You are entirely correct,

However, nothing precludes using both approaches when appropriate.

Allows selection of minimum bleed resistor to maintain minimum load current for the choke (when a choke is used),

and

A lower resistance to safely and quickly discharge upon turn off.

[morfeas]

Contacting a small value bleed resistor on power off gave a big thumb on my power amp.