Any Ideas For A 35V DC Voltage Regulator?

What are the strobe circuits actual rated working voltages?

If it's one of the those universal types with the wide range input voltage like 12 - 36 VDC they don't really have any issues with being ran slightly above that 36 volt range.

On a 36 volt forklift application the actual battery voltages can be up to around 45 volts while charging or just coming off of a full charge and all the electrical and electronics devices rated for 36 volt operation must be able to handle that over voltage without problem.

Its similar to how a vehicle's electrical system is rated at 12 volts but in reality it can run at times up around 16 volts and still be within spec.

Strobe circuit has its own power feed. Concern is powering my SS relay for a 35V bulb. LEDs are sensitive.

Not sure you can get the LT1038 anymore, they are obsolete, and with the numbers you provided, it is a job requiring at worst case to dissipate/cool 80W. ([43-35]*10)

It will be much easier if you parallel some devices; it is still 80W but not concentrated in one package.

My pick would be LT3080 in TO220-5 case, x9 or x10 in parallel (see data sheet). With only 8W on each, the internal chip temp rise will be only 24C above the heatsink temperature... and with 10 in parallel it will tolerate if one of them failed.

Also, since the max IN to OUT voltage difference is 8V, it will survive the 43V input as long as there is no output short.

LT3080 (TO220) is around $3 each directly from LTC here.

You may prefer the following simpler solution:

Use one LT3080, with its output driving the base of a 2N3055 output-transistor, similar to the Darlington emitter-follower circuit below.

'+Vcc' is your input 43V, and 'Vin' is functionally similar to the SET pin voltage that develops on R-set of the LT3080.

With the transistor case at 25C, it can handle up to 115W.

I'm running parallel adjustable regulators now for portable testing purposes. Size is such an issue. I'm looking at these chips you just mentioned. Great idea. Thanks.

"similar to the linear LT1038 chip?" Basically one can build a DC Voltage Regulator according to any desired choice by selecting / using discrete components. The key is the selection of the proper type of Zener diode(s) and power output devices to be used. The zener voltage will determine your reference voltage level while the output power capacity as determined by the rating of the selected output device(s).

If you decide to parallel regulators, be aware the devices will try to regulate each other, overheat and die! (Same rule for separate power supplies.)

Seen this mistake made a number of times -- including trying it myself --- once!

I did manage to use current limiting resistors for a supply where the exact voltage did not matter. Search "High Current Power Supply Circuit" and look around.

Here's one:

http://www.free-electronic-circuits.com/circuits/high-current-power-supply.html

Lm317 is an adjustable regulator which can be used in this type of design. Still available at R---o S---k last I checked.

How do you think the LT3080 will respond to a constant 45V input feed? The input batteries will run anywhere from 35V to 45V depending on charge state. This this would hold up?

This would appear to be the perfect usage of the LT1074/LT1076 family of chips. Up to 60 volts DC input, output voltage programmable from 2.5 to 50 volts DC at 5 amps, more than enough for almost any strobe circuit.

BUT:-

I also have a circuit that I use from Elektor, that combines two of the chips for outputs of up to 10 amps at the voltage selected, if you want a copy, send me a "proper" email address via the CR4 email (DO NOT POST YOUR EMAIL ADDRESS HERE PLEASE), and I will send you a filzip file with all the build details.

This goes for anyone who wants a copy of course!

Andy yes I'd love to see it. bronxvilletechnical@aol.com (remove the nical from the word).