Increasing the current capability of this circuit
Increasing the current capability of this circuit
(OP)
Any ideas without having to increase the value of R1 or R2 (they are 2M and 1M each)?
D1 , D2, D3 are DIACS that let voltage pass when its 24V or above.. the LEDs are just indicators of High Voltage… the more voltage the more they lit thanks for any tips
D1 , D2, D3 are DIACS that let voltage pass when its 24V or above.. the LEDs are just indicators of High Voltage… the more voltage the more they lit thanks for any tips





RE: Increasing the current capability of this circuit
Is this homework?
RE: Increasing the current capability of this circuit
The OP's post at top is too vague.
RE: Increasing the current capability of this circuit
RE: Increasing the current capability of this circuit
3Mohms * 20mA = 60k Volts
60kV * 20mA = 1200 watts
RE: Increasing the current capability of this circuit
RE: Increasing the current capability of this circuit
RE: Increasing the current capability of this circuit
There are much better ways of doing it. Or is this a VERY SPECIAL APPLICATION?
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: Increasing the current capability of this circuit
Does anybody have an alternative design / ideas for doing this? Thanks
RE: Increasing the current capability of this circuit
Add a capacitor to get the flashing and select size of capacitor and series resistor between C and LED to suit.
The string of diacs is not needed. Or do you mean to protect the supervising circuit with them? Why? There are far too few data given for any design engineer to comment seriously on this. Tell us what the application is. Not only that is is supposed to warn for too high voltage. Tell us at what level it shall warn. Tolerances on that level. Temperature range. Constraints on power consumption. Needed visibility - remember that the eye cannot see very short flashes if they are not intense enough.
But, main message is: add C. And use parallell resistors to avoid premature triggering of the series connected diacs. If they are needed at all.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Increasing the current capability of this circuit
RE: Increasing the current capability of this circuit
RE: Increasing the current capability of this circuit
Please define scope of design function and current specs.
For HV indicators, use a HV zener not DIACS, which are negative resistance devices . Then the LV LED's can go in series with the zener to indicate zener limit .. It goes without saying that the LED's need reverse protection diodes built in or added on. All LED's begin to fail at -10V and are rated for -5V. that includes EOS discharge.
RE: Increasing the current capability of this circuit
Where do you get that? I've tessted large numbers of LED and have never seen any leakage or damage under -200V. I've run tests with these powered at 120V line voltage for months with no damage and even on early technology versions over 30 years old.
RE: Increasing the current capability of this circuit
Easy to test... hook an LED to a 9V battery backwards, then reverse it to be forward-biased again (briefly). Two shiny dimes and a rusty nickel it still works...
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Increasing the current capability of this circuit
RE: Increasing the current capability of this circuit
It still may be latently toast. Excessive supply voltage is one approach to accelerating a life test. Depending on the duration of the exposure to accelerated conditions, your processor may experience premature failure. OR, it already has a failure, but you just haven't processed anything through the part that is already damaged.
TTFN
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