Using a switch to bypass 555 timer? - Electronic Circuits Projects Diagrams Free

sjaguar13 · 29th June 2003, 10:28 PM

I have LEDs that blink using a 555 timer. I want them to be able to stay on. How would I use a switch to do this? Would I need a SPST switch?

afs87 · 1st July 2003, 06:22 PM

Hello,

When you say 'stay on' do you mean you want them to stay on after the first flash? If so I would recomend wireing the 555 as a monostable and connecting an inverter and thyristor to the output. You could have a switch on the tyristor if you want to turn the latching on or off (a standard on-off off-on latching spst should do). If not please explain.

afs87

sjaguar13 · 2nd July 2003, 08:59 PM

I want to be able to make them flash, then flick a switch and they are no longer flashing.

bryan · 2nd July 2003, 10:23 PM

Why not add a on/off switch to the power supply?? Or do you mean stop flashing but still stay on

sjaguar13 · 3rd July 2003, 12:31 AM

Yeah, I want it to stay on, but just not flash.

pebe · 3rd July 2003, 02:50 PM

One way is to wire the 555 as an astable, with threshold and trigger wired together. From their junction, connect the timing cap to ground and the timing resistor to output.

To make the output stay high, switch the th/tr junction to ground - to make it stay low, switch the junction to +ve rail.

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29th June 2003, 10:28 PM	(permalink)
sjaguar13	Using a switch to bypass 555 timer? I have LEDs that blink using a 555 timer. I want them to be able to stay on. How would I use a switch to do this? Would I need a SPST switch?

1st July 2003, 06:22 PM	(permalink)
afs87	Please Specify Hello, When you say 'stay on' do you mean you want them to stay on after the first flash? If so I would recomend wireing the 555 as a monostable and connecting an inverter and thyristor to the output. You could have a switch on the tyristor if you want to turn the latching on or off (a standard on-off off-on latching spst should do). If not please explain. afs87

2nd July 2003, 08:59 PM	(permalink)
sjaguar13	I want to be able to make them flash, then flick a switch and they are no longer flashing.

2nd July 2003, 10:23 PM	(permalink)
bryan	Why not add a on/off switch to the power supply?? Or do you mean stop flashing but still stay on

3rd July 2003, 12:31 AM	(permalink)
sjaguar13	Yeah, I want it to stay on, but just not flash.

3rd July 2003, 02:50 PM	(permalink)
pebe	One way is to wire the 555 as an astable, with threshold and trigger wired together. From their junction, connect the timing cap to ground and the timing resistor to output. To make the output stay high, switch the th/tr junction to ground - to make it stay low, switch the junction to +ve rail.