cap discharger

[fiend138]

Hi does anyone know where to get the neon for this cap discharger and the clips also? The link doesn't seem very distinctive about what the neon is.

http://1176neve.tripod.com/id29.html

thanks
max

[gez]

Drain using a resistor or two (watch the power ratings) and just use a DMM to measure how much voltage is left on the caps.  Be careful what you touch when connecting the meter probes!

[gez]

PS  Didn't look at the article in any depth but presumably the 'Neon' is a neon bulb/indicator.

[petemoore]

  I use a 5w [but 10w'd hold], 22k resistor.
  It is soldered to a bright Yellow, flexible wire to alligator clip.
  The end of the resistor is hooked on a cap using the insulated wire/shrink insulation, and I have a 'strap' of electrical tape around the resistor.
  I wrap the yellow wire around the power switch, this keeps tension on the resistor hook/cap lead connection, also reminds me to disconnect that resistor before power up. The electrical tape is a second reminder, and would start smoking if the resistor has to 'eat' a whole lot of current [like if it was left in during power up].
  I just leave the drain R, measure voltage under say 50v then start looking at the amp.
  Caps can 'regrow' voltage potential after draining.
  What'd be a great feature is an LED Voltage indicator, near the high voltage sections, that turns on when voltage rises to ~30v or more...
  {I've got the methods down that remind me to take the resistor off, tieing the yellow wire to the switch is probably good enough, but remembering to PUT the resistor on is the most important task}.

[LyleCaldwell]

Ah, you guys are wimps.  Nothing like a screwdriver with chunks zapped out of it!

[Connoisseur of Distortion]

i have a 20W 30k resistor. big enough to comfortably hold without going near the ends. a must-have.

[R.G.]

What baffles me is how any designer worth his pay does not design in bleeder resistors that make the caps safe within, say, 30 seconds. In my power supply design years, we were REQUIRED to show that our designs made every voltage in the circuit be less than 42Vdc within 15 seconds of AC power off. That's a pretty stiff requirement, but I still view any power supply cap with over 40Vdc on it without a bleeder resistor as a quick indicator that the "designer" is still using training wheels.

Before we get off on draining power caps in effects, for all of those who don't know, these guys are discussing power supply capacitors in units that have voltages over 40Vdc, perhaps much over 40Vdc in the case of tube supply circuits.

[petemoore]

  the Electric Co.'s love the extra current draw !! Actually I wouldn't know what that 'could' be, but judgeing from the heat output...the case which I have had to look at is 22k tapping off a 5e3's B+ HV Caps.
  Voltage detector warning light? I imagine there is such a thing...whether that'd be cost effective for every amp...but it'd would be a nice bench item.

[no one ever]

What baffles me is how any designer worth his pay does not design in bleeder resistors that make the caps safe within, say, 30 seconds. In my power supply design years, we were REQUIRED to show that our designs made every voltage in the circuit be less than 42Vdc within 15 seconds of AC power off. That's a pretty stiff requirement, but I still view any power supply cap with over 40Vdc on it without a bleeder resistor as a quick indicator that the "designer" is still using training wheels.

Before we get off on draining power caps in effects, for all of those who don't know, these guys are discussing power supply capacitors in units that have voltages over 40Vdc, perhaps much over 40Vdc in the case of tube supply circuits.

i assume you've implemented bleeder resistors in your workhorse amps? (so are there "DO NOT OPEN" stickers on em?  )