Schematic for children's auto-off flashlights

[snovotill]

Schematic for children\'s auto-off flashlights

I just drew out the schematics for a couple of the more popular children's Auto Off flashlights. Here:
http://members.shaw.ca/novotill/FlashlightTimers/index.htm

 

[Bandgap]

Re: Schematic for children\'s auto-off flashlights

Just a point...

The switch-capacitor junction on the first circuit could do with a resistor to 3V.

Or there is a slight chance the capacitor could acquire 3V charge and never trigger the circuit

Steve

 

[Doug S]

Re: Schematic for children\'s auto-off flashlights

These circuits use more componets than necessary. For a momentary PB switch as the actuator, just three components are necessary, a mosfet, resistor, and capacitor. Configured with the RC parallel combo across the mosfet gate-source. PB used to charge cap to turn on mosfet.

 

[Roy]

Re: Schematic for children\'s auto-off flashlights

Had a friend in the Army that built an automatic dimmer into the light switch in the kids bedroom. Put the kids to bed, hit the switch on the way out and 10 minutes later the kids and light were out!

 

[snovotill]

Re: Schematic for children\'s auto-off flashlights

Thanks very much for catching that Steve. I've double checked the circuit board and corrected the drawing. I apologize PROFUSELY for not getting it right the first time.
...Stepan