Does this 4011 flasher work?

[dougnsandiego]

Found this circuit and am hoping it does what i need - flash the LED at the rate of 240 per minute. Have no idea how to tell if the resistor/cap values are set properly to do this.

Anyone know how to determine what this will CD4011 circuit actually do?

 

[alec_t]

It doesn't do what you want. One of the four gates oscillates.....at about 2 MHz !

Anyone know how to determine what this will CD4011 circuit actually do?

Simulate it in LTSpice etc.

 

[dougnsandiego]

Darn. Don't know how to simulate / use Spice.

Is it a problem with the resistor/cap values?

 

[dougnsandiego]

here is the original schematic ---

Maybe I didn't format my version correctly ....

Does this ORIGINAL schematic - which I copied to make up my layout - have the same problem?

 

[Reloadron]

Right off the top if you gate the MOSFETS ON they produce a dead short across your supply. Where is the load?

Ron

 

[House0Fwax]

Furthur to what Ron said, the on/off switch will also short out the supply.

 

[dougnsandiego]

Yeah, that didnt make sense to me either - I just used the CD4011 part of the circuit, took output from pin 4 to a small transistor whose output (if pin 4 was high) lit the strobe. Have not tried to breadboard yet - thought it wise to ask if the CD4011 design would produce the flashing output before even starting --- and, at what rate.

Any way to check that from the circuit? I'm not even sure why the inputs of 3 of the amps are shorted together.....

 

[alec_t]

Is it a problem with the resistor/cap values?

Yes. But there are other problems too.
Check this, for a simpler circuit using just one CMOS gate as an astable circuit:
https://www.electro-tech-online.com/threads/what-is-a-coil-tap.472/