Dear Group,

I need to regulate (lower) ~340V DC to ~10V DC for supply voltage to an opto driver to gate an SCR. The best three terminal regulator I can find is the TL783 which will work to 125V DC. It shows a circuit for increasing the voltage to 200V (see attachment)
The transistor is rated for 400V, so could this circuit be used at 340V?
I was thinking of using an MJE5742G (2x Hfe). Would it work the same?
Should I lower the zener voltage (it is now very close to the regulator max V)?
I would use a lower R2 for 10V.
Is there an easier way to do this?

Thanks so much!
Mike

 

Since you didn't provide a schematic, I looked up your other threads - and discovered that you are still referring to a circuit that we do not permit to be discussed on this forum in accordance with the Terms of Service paragraph 6, which reads:

6. Restricted topics. The following topics are regularly raised however are considered "off-topic" at all times and will result in Your thread being closed without question:

• Any kind of over-unity devices and systems
• Automotive modifications
• Devices designed to electrocute or shock another person
• LEDs to mains
• Phone jammers
• Rail guns and high-energy projectile devices
• Transformer-less power supplies

The topic you wish to discuss is not welcome on these Forums, as it is inherently unsafe, and I urge you to discontinue your attempts on that project; it is likely to cause you severe injuries or death.

 

This happens with depressing regularity. If you insist on making a tranformerless power supply please take it elsewhere, otherwise provide complete schematics.

Also, word is a lousy graphics program and a great virus vector. Please use .gif or .png files instead.

I am closing this thread because of the rules violation.