I need to make a multiplier to take the 5KV from my neon sign transformer to 50KV. Can someone tell me what voltage rating the diodes and capacitors should have? I know they don't have to have a rating of 50KV but what would be a safe rating? It's been a while since I've made one of these things. BTW my neon sign transformer is a 15KV 30ma but I don't want to take it that high. I want to variac it to 5KV and then use the voltage multiplier.
50KV multiplier from 5KV neon sign transformer
Jan 17, 2011
6 Replies
They need to handle the 5kV. Because on a multiplier, each stage is getting bummped with an offset of 5KV per diode.
Multiply by both factors of 2 and square root of 2, plus safety factor.
All diodes and most capacitors involved will by-design experience voltage of transformer output RMS voltage times twice the square root of 2.
That means 14.2 KV, 15 KV rating with awfuly small room for error...
Unless yu want to "Variac"-down this arrangement to 5 KV peak rather than RMS (3.5 KV RMS, resulting from 28V input to a 15 KV transformer), in which case you are mostly pushing 100% of the ratings of 10KV voltage-rated parts.
- Don Klipstein (don@misty.com)
The microwave ovens also use a voltage dividing resitor across each diode to insure voltage division, evenly.
None of the diodes will be rated high enough for the total voltage and if a few leaks the last ones will get zapped without some voltage division insurance. I believe a string of about 10megOhm resistors was used in the last one I saw.
All diodes and most capacitors involved will by-design experience voltage of transformer output RMS voltage times twice the square root of 2.
That means 14.2 KV, 15 KV rating with awfuly small room for error...
Unless yu want to "Variac"-down this arrangement to 5 KV peak rather than RMS (3.5 KV RMS, resulting from 28V input to a 15 KV transformer), in which case you are mostly pushing 100% of the ratings of 10KV voltage-rated parts
In article , Jamie wrote: sinebar wrote: I need to make a multiplier to take the 5KV from my neon sign transformer to 50KV. Can someone tell me what voltage rating the diodes and capacitors should have? I know they don't have to have a rating of 50KV but what would be a safe rating? It's been a while since I've made one of these things. BTW my neon sign transformer is a 15KV 30ma but I don't want to take it that high. I want to variac it to 5KV and then use the voltage multiplier. They need to handle the 5kV. Because on a multiplier, each stage is getting bummped with an offset of 5KV per diode.
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Well I did some investigating and came up this design: I will use 6
20KV doorknob capacitors and 6 HV03-12 12KV PIV High Voltage Diodes in a typical voltage multiplier configuration. With 6KV input I should get about 51KV according to Instructables.com. Here's their calculations on the websiteTo calculate the expected voltage at the output with a given input and number of stages, plug the numbers into this formula: Eout =3D (2 x Ein) x S x 1.414 Eout is the Output Voltage, Ein is the Input Voltage, and S is the number of stages in your design. I used a 6,000 VAC Oil Burner Transformer for my input and built 3 stages. Eout =3D (2 x 6000) x 3 x 1.414 Eout =3D 12000 x 3 x 1.414 Eout =3D 36000 x 1.414 Eout =3D 50,904 volts
please give opinions and advice.
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. rWhat value capacitors in pf or uf? At 60 Hz, the capacitors have to be pretty large in value if you are expecting to draw any current at the 50 kV level. What are you going to do with it except shock the life out of whatever touches it?
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10 nF capacitor for a flashtube pumped dye laser.Join the Discussion
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