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I have a quartz clock movement with a seperate chime module that plugs into the clock movement. The signal from the quartz movement makes the clock chime every hour. The output signal is very small its 0.4volts dc. I want the signal to operate a 5volt relay so that it can run a motor every hour that it is supposed to chime. Please help, i have tried a couple things and took it to some phone repair shops to help me out but they dont get me- since I have zero experience in electronics I can only do this project if i have the correct information for parts and a diagram.

0.4 V is a little bit low for a relay and even for a single transistor (most BJT require at least 0.6 V and quite low for most MOSFET (Metal Oxyide Semiconductor Field Effect Transistor). Note that transistor can easily outperform relay at "low" voltages and are probably preferable to relay in your case.

An MCU (Micro Computer Unit, an Arduino or the like), its ADC (analog to digital conversion) could easily detect that 0.4 V though, and send a reasonable output on another of its IO (Input/Output) pin to a MOSFET which, in turn could turn on a motor (and I suspect that you may want to turn it off too, if only timing is required, the MCU can handle it too, no extra hardware other than the MCU, the MOSFET and the electrical alimentation fo the MCU and the other alimentation for the motor).

That is a view of the ground from a height of one kilometer high in altitude, I agree, but that view could help in the path to be selected, on the ground.

instead of using the signal from the clock movement, what if I use the chime signal from the speaker. the chime has a seperate powered by 2AA batteries (3volts)

If the speaker is NOT used for anything else. And the motor will stop turning as soon as the speaker will turn off too. Is it what you want?

It is generally unwise to build from a side effect rather than on the main effect for reason of maintenance versus modifications which may be brought in the future.

But it is definitely easier to work with a signal of 3V rather than one of only 0.4V. 3V is fine to turn on a transistor, but maybe not so for a relay.

Here is a nice discussion about what to do and not. Don't use the initial circuit, it is flawed, get the discussion to better understand the principles. The PWM signal, in your case, would be your speakers (if you use that way of doing things, even if I don't recommend it for long term stability of the design itself, since you may end up with poor control on how the motor behaves).

Hello Vanderghast. Thanks so much for your response.. Basically the Motor is supposed to take the place of the chime- so the chime goes on for as long as the time of the day. so the motor will run longest at 00:00 and 12:00.

I tested the chime output and because it takes 2 batteries AA (the output at the chime is around 2.9 Volts. I would like the motor to run off that if its possible to open that relay. The small electronic component of the chime looks very delicate. I dont know how to upload pictures however maybe you can email me:

info.delta9@gmail.com

Please note that i have absolutely zero experience / knowledge in electronics. just a basic understanding of electrical concepts. so any advice you give me I will have to go to a local electronic technician with the parts to get him to make the relay for me.

I tested the chime with a 5volt input from a charger.. and the output at the chime is 5.23Volts when the chime goes off.. if this helps we can use a 5volt without frying the electronics.

A common way to do this is with a transistor (like a NPN BJT sports games az) acting as a switch, or a simple op-amp comparator circuit. The transistor would take that 0.4V signal as input to its base, and then switch on a higher voltage (like 5V from a separate power supply) to energize your relay coil. You'll also need a current-limiting resistor for the transistor's base and a flyback diode across the relay coil.

Do you have a separate 5V DC power supply available for the relay and the amplification circuit, or are you hoping to power everything from the clock's existing power source?

a small “signal-to-relay” driver circuit is required; the quartz movement alone can’t power the relay. soflo wheelie life

I understand your challenge! To use a very low voltage signal (0.4 V DC) from your quartz clock movement to trigger a 5 V relay, you’ll need a simple circuit to amplify that signal.

A common and beginner-friendly approach is to use a small NPN transistor (like a 2N2222) as a switch:

The 0.4 V signal goes to the transistor’s base through a resistor (around 10kΩ).

The transistor switches a 5 V supply to energize the relay coil. Make sure to include a diode (like 1N4001) across the relay coil terminals to protect your circuit from voltage spikes. Power the relay coil from a stable 5 V source (battery or adapter). you can check my website for more exp: mr flip