I need circuit to ON/OFF led when push button is long pressed(2 to 5 sec) without micro-controller or programming. Required any kind of simple circuits, can anyone help me?
Yes, the circuit will work down to 3V.Would this work for a low amp 3.7v circuit?
--- Bill of Materials ---Is there a parts list for this?
You can make it quite small depending upon whether you are up to building in on a PCB with surface-mount parts.How small of a package do you think you could make this
No, because U1 needs a fast clock risetime to work properly.If I replace U2 by a RC time delayed circuit, will it work normally?
Set the output to OFF upon power-up.What is the function of R3, C2 ?
Only if you don't care about the state of the output when it's powered up.May I connect preset of U1 to GND?
It may not reset upon power-up if the power-up ramp time is slow.Replace C2 by a small cap?
HiYes, the circuit will work down to 3V.
The simulation below shows it working at 3.7V.
View attachment 157561
--- Bill of Materials ---
Ref. Mfg. Part No. Description
C1 -- -- capacitor, 22µF
C2 -- -- capacitor, 22µF
D1 OnSemi 1N4148 diode
D2 AOT AOT-2015 diode
D3 OnSemi 1N4148 diode
Q1 NXP 2N2222 bipolar transistor
R1 -- -- resistor, 237K, 1%, 0.1W
R2 -- -- resistor, 1K
R3 -- -- resistor, 100K
R4 -- -- resistor, 4.7K
R5 -- -- resistor, 10K
R6 -- -- resistor, 100
U1 (unknown) CD4013B (unknown 3rd party model)
U2 (unknown) CD4013B (unknown 3rd party model)
You can make it quite small depending upon whether you are up to building in on a PCB with surface-mount parts.
Dear Sir :Here's the LTspice simulation of a circuit that should do what you want.
D2 is your LED.
The CD4013 is two flip-flops in one package. You must add power and ground to that chip (not shown).
The delay time is determined by the value of R1 and C1.
The values shown give a delay of about 3.5s.
View attachment 118095