Reed Switch Operated Power Relay

Hi All. I'm a graduate student and electronics is not my field, but I have to build an apparatus for my experiments and I'm very stuck. The device being operated What I’m ultimately hoping for is to draw a detailed circuit diagram so I can go out and buy the parts/pieces to build and test this setup. Here's the explanation what the circuit needs to do:

Please refer to the attached very crude diagram. The supply end of the circuits plugs into a regular wall socket for power. The power is routed through a relay switch which will operate devices on the receiving end when the circuit is closed. The power relay switch is normally open. In order to activate or close the power relay, a reed switch will be used. But here's the kicker... the reed switch has to be powered by the same power supply as the relay (i.e. from the wall outlet) rather than a battery. the reed switch would work similar to the ones mounted on security doors so that when a magnet is brought close to the reed switch it is activate (closed) and that triggers the relay to also close causing power to flow through the relay. The last thing is that there be a small LED after the relay switch that confirms that power is flowing through the relay, i.e. the receiving end of the circuit is energized. The final constraint is that all this be as compact as possible, so if using a solid state relay instead of a mechanical one would reduce size then that's what I would go with (suggestions please). And also the power relay has to be able to support up to 10amps - 15amp.

I don't know what (if anything) is needed to convert the AC power from the wall socket (120v) into DC power for the reed switch. Not sure if that's even necessary. I'm really circuit illiterate so I apologize. If you could give me as much
detail as you can on the parts to use (to buy) that that would be a huge help. It'd be great to know what to ask for when I go to shop for the parts. I really appreciate any help, especially diagrams, anyone can suggest. Please keep in mind that the more compact the set up the better because it has to be fit into a very small compartment. Thanks.

First idea to use a Solid State Relay, 10-15 amps, with 100 to 280 VAC control input. The reed relay contact to be mounted on the input, a supplementary LED + antiparallel diode + series capacitor connected on the output for monitoring purposes. Estimated dimensions (mm) : 57(H) x 44.5(W) x 23(D)
**broken link removed**

mister_rf said:

First idea to use a Solid State Relay, 10-15 amps, with 100 to 280 VAC control input. The reed relay contact to be mounted on the input, a supplementary LED + antiparallel diode + series capacitor connected on the output for monitoring purposes. Estimated dimensions (mm) : 57(H) x 44.5(W) x 23(D)
**broken link removed**

Click to expand...

Thanks for your reply. So how would I mount the reed switch? I would have to be in parallel not series right? Because if I put the reed switch in series with the relay it would get fried I think! Anyway, thank you and if you have any additional suggestions of if you can scribble quick diagram... it would be a life saver! Thanks. - AJ

This is a simple diagram of the reed switch and relay setup. They use house power as specified.

The reed switch doesn't care if DC or AC is going through it.

The relay coil should be okay with 60 Hz AC.

Driving an led from 120 VAC takes another circuit. It can be done more efficiently by using a capacitor to drop voltage rather than a resistor.

Here is the circuit diagram along with the parts list for the circuit to added to this relayed schematic.

No need for all 4 diodes, use only one...

mister_rf said:

No need for all 4 diodes, use only one...

Click to expand...

mister_rf - could you please post that last diagram again? For some reason it's not showing up when I log on. Thanks. - AJ

The diagram in post #6 shows up as a thumbnail at first.

I clicked it. It took several seconds for it to load and show onscreen.

Some diagrams take more time than others.

No need for all 4 diodes, use only one...:grin:

Click to expand...

If you use only one diode, it will work but the stability of the LED will not be assured. Try it and see the result in long run not in few seconds or minutes. I am using this arrangement for the last one year without any problem.

I tried that a long time ago (back in the 90's), still works...

In case you want to use ONE DIODE change the capacitor from 220nF to 100nF. Safety is there.