Re: We are KILLING our HV diodes...?

A bit of chatter back and forth with Hans, he believes that t three watt 1M
resistor will work fine, just connect it to the end of the jumper that you
put under the anode cap. I think that will cover the voltage issue for me
as well. So, anyone have any 1 Meg 3 watt resistors? Check your local TV
parts suppliers...

John :-#)#

At 08:02 AM 4/22/2000 , you wrote:
>Now that I have your attention <grin> I thought I would pass on a warning
>I received from an Electronics Engineer this morning:
>--------------------------><-----------------------------------------
>To: <jrr@flippers.com>
>Subject: Grounding picture tube
>
>I've seen your pages about handling video monitors.
>However you're very secure and precise with this there is one thing
>you forgot to mention.
>You should NOT ground the anode of the tube DIRECTLY to ground.
>ALWAYS use a resistor of 1 Mega ohm between earth and anode.
>Direct grounding can cause the cascade rectifier to die.
>Using 1 meg won't affect the discharge at all and will completely
>discharge the remaining high tension.
>
>Yours sincere.
> Hans Balk
>(electronics engineer)
>-------------------------------><-----------------------------------
>Hans here has raised a good point and this might explain why the B&Y XY
>monitor HV diodes are failing-'cause we are killing them! @!#$!@#$@.
>
>I have asked him to elaborate a bit on the theory behind this , but in the
>meantime, might I recommend that you all follow his advice? Also to get a
>1 meg diode to do this job, remember that we are dealing with 12 - 24KV
>here, so a regular 1M 1/4 watt resistor won't cut it. It will arc over
>internally...use a series of ten 100K 1/2 watt resistors (2Kv4 max. across
>each??), insulated with a couple of layers of HeatShrink, that is about
>ten or more inches in length. This is just off the top of my head, I
>suspect that this design is not quite right yet, perhaps twenty 50K
>resistors (1Kv2 across each) is better...there are special HV resistors,
>scrounge around...
>
>If you have an stand-alone HV meter probe, so much the better, allow it to
>discharge the tube...
>
>John :-#)#
>
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
> http://www.flippers.com
> "Old pinballers never die, they just flip out."
>
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  John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
  Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
  http://www.flippers.com
         "Old pinballers never die, they just flip out."

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Received on Sat Apr 22 11:42:57 2000