High voltage DC indicator LED?

Status
Not open for further replies.
U

uoficowboy

Full Member level 3
Joined
Apr 4, 2009
Messages
169
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,298
Location
Seattle, Wa, USA
Activity points
2,964
Hi - I'm working on designing a board that will have a high voltage DC input. The voltage could be anywhere between 0 and 5KV. I'd like an indicator LED to light up when the voltage is at a dangerous level. Say - 50V. The high voltage is generated on a different board and it is not a strong power supply - so I don't want to put much load on it. The best idea I have is to make a massive voltage divider and run an LED with a comparator. Can anybody think of any better ways of doing it? That approach annoys me as those resistors will have to be a huge value to keep from drawing too much current.

Thanks!
 

Hi
I think, these is only way...
You can have a HV resistor at ca 20-25x5x2mm (Vishay), you must it have the 5KV need crepage distances, not only dissipation is volume specifing. Then I would apply guard ring around the attenuated-HV parts...
K.
 

    U

    uoficowboy

    Points: 2
    Helpful Answer Positive Rating
karesz said:
Hi
I think, these is only way...
You can have a HV resistor at ca 20-25x5x2mm (Vishay), you must it have the 5KV need crepage distances, not only dissipation is volume specifing. Then I would apply guard ring around the attenuated-HV parts...
K.
Click to expand...
Hi Karesz - are you referring to the Vishay HTS series? Those look nice, though they seem to be difficult to get.

Can you tell me what a guard ring is and how you would implement it?

Thanks!

-Michael
 

Hali Michi,
No, I did referred to the newer families,FHV100, I saw an article so 2 weeks ago over their & I have to search for that, but yours are good too...
I know as another good HV Resistor deliverer too: Victorin & Metallux_from Metallux i .e.: www.metallux.de/en/products/high-voltage-resistors/high-voltage-divider-series-1000.html _I did used good 10 years ago some similares as yet you can order from Vishay too...
K.
P.s.:
Guarding means: you have to design a GND line (lowest impedance), a ring, around the pins, from (or to) where is some leakage unwished to the rest of your circuit!
In your case, dont forget after attenuator a serial resistor + an HVTtransient Transorber to forseen_ if the attenuator R to GNd will be wrong, it has to eliminate/limit the HV/current into your ADC...
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…