Replace reed switch with something else to continually close/open circuit - Electronic Circuits Projects Diagrams Free

ghh3rd · 22nd October 2009, 08:44 PM

I have a device with a magnetic reed switch.

I want to replace the reed switch with something that will close/open the circuit continually, adjustable to anywhere from perhaps once per second to perhaps 4 times per second.

I imagine that the heart of this would be a 555 chip, but that's about all I (think) that I know. I have never constructed anything like this before.

Are there any simple plans anywhere to accomplish something like this?

Thanks,

Randyu

crutschow · 22nd October 2009, 10:01 PM

Need to know the voltage and current the reed switch is switching.

Why not just control the reed switch with a 555?

ghh3rd · 22nd October 2009, 10:14 PM

Good idea. Leaving the reed switch in place, and using a 555 to control it would definitly seem like a better solution.

Now, can anyone point out a good way to do this? Only one speed is necessary. Perhaps I could tweak the circuit until I get to the desired speed?

Thanks,

Randy

ghh3rd · 23rd October 2009, 01:26 PM

Can you please elaborate on how to use the 555 to control the reed switch?

Thanks - Randy

Gayan Soyza · 23rd October 2009, 02:52 PM

Configure 555 to Astable configuration.Google for NE555 Astable circuits.

ghh3rd · 23rd October 2009, 07:12 PM

Gayan,

Will do -- but the reed switch requires a magnetic field; how will the 555 actually 'control' the switch?

Sorry if my question sounds obvious, but I'm new at this. I'd really like to get into building and eventually being able to design components.

Randy

crutschow · 23rd October 2009, 11:00 PM

I take it the reed switch is activated by a magnet normally.

In that case you would need to wind a coil around the switch. Any small tube (straw) that just fits over the reed should work as a coil form. Then you need to wind many turns of as fine a wire as you can find (such as 30Ga or finer). You will have to experimentally determine how many turns and how much current it takes to activate the switch. From that you can calculate the voltage and resistance in series with the coil will provide the required current.

Otherwise just substitue a reed relay for the reed switch. They have the coil already wound.

ghh3rd · 24th October 2009, 02:20 PM

Thanks for the explanation crutschow.

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22nd October 2009, 08:44 PM	#1
ghh3rd	Replace reed switch with something else to continually close/open circuit I have a device with a magnetic reed switch. I want to replace the reed switch with something that will close/open the circuit continually, adjustable to anywhere from perhaps once per second to perhaps 4 times per second. I imagine that the heart of this would be a 555 chip, but that's about all I (think) that I know. I have never constructed anything like this before. Are there any simple plans anywhere to accomplish something like this? Thanks, Randyu

22nd October 2009, 10:01 PM	#2
crutschow	Need to know the voltage and current the reed switch is switching. Why not just control the reed switch with a 555? __________________ Carl Curmudgeon Elektroniker

22nd October 2009, 10:14 PM	#3
ghh3rd	Good idea. Leaving the reed switch in place, and using a 555 to control it would definitly seem like a better solution. Now, can anyone point out a good way to do this? Only one speed is necessary. Perhaps I could tweak the circuit until I get to the desired speed? Thanks, Randy

23rd October 2009, 01:26 PM	#4
ghh3rd	Can you please elaborate on how to use the 555 to control the reed switch? Thanks - Randy

23rd October 2009, 02:52 PM	#5
Gayan Soyza	Configure 555 to Astable configuration.Google for NE555 Astable circuits. __________________ Gayan My Website http://gsmicro.blogspot.com/

23rd October 2009, 07:12 PM	#6
ghh3rd	Gayan, Will do -- but the reed switch requires a magnetic field; how will the 555 actually 'control' the switch? Sorry if my question sounds obvious, but I'm new at this. I'd really like to get into building and eventually being able to design components. Randy

23rd October 2009, 11:00 PM	#7
crutschow	I take it the reed switch is activated by a magnet normally. In that case you would need to wind a coil around the switch. Any small tube (straw) that just fits over the reed should work as a coil form. Then you need to wind many turns of as fine a wire as you can find (such as 30Ga or finer). You will have to experimentally determine how many turns and how much current it takes to activate the switch. From that you can calculate the voltage and resistance in series with the coil will provide the required current. Otherwise just substitue a reed relay for the reed switch. They have the coil already wound. __________________ Carl Curmudgeon Elektroniker

24th October 2009, 02:20 PM	#8
ghh3rd	Thanks for the explanation crutschow.