Soft start circuit

[mesa232323]

Need diagram or instructions on how to make a circuit that runs resistance with a resistor for a few seconds before automatically switching to direct drive. It will switch back to using the resistor everytime it is fired.
The circuit needs to be small enough to fit in a small circuit board that will fit in the tail cap under the spring. I plan on making a circular circuit board under the spring isolating the ground as I will be controlling the current through the ground. I will be using this with a 6D mag and a philips 5761.

 

[SVARO]

Interested

 

[nightshade]

Use the CPF archives and search for Willie Hunt's Low Voltage Regulator (LVR) system. LVR variants enable a 50msec soft-start, enables the bulb to be driven at max power all the time, and it's regulated.

And some more external info: https://legacy.cs.indiana.edu/~willie/lvr.html

 

[mesa232323]

I eventually figured out a circuit. All I needed was an 8 amp, 1 ohm thermistor. I was able to power a Philips 5761 on 6x D NIMH without flashing the bulb on freshly charged cells.

Sent from my SM-G981U using Tapatalk

 

[alpg88]

you need inrush current limiter, digikey sells those for like few bucks, i used one with wa1185,

 

[TheBestTexan]

you need inrush current limiter, digikey sells those for like few bucks, i used one with wa1185,

Been trying to do some research on a similar build I've had planned. Everything seems to work out except for the thermistor. I feel like you used something similar due to this type of ICL thermistor being for sale on digikey. Only problem I'm worried about now is the heat from the thermistor itself, is it as much of an issue as I think it will be? or will it star relatively cool and be fine near the battery pack.