Information

In 2003 I made a metronome, which is good both for determinate a beat when we play music and also good as a tuner. Whole project started in 2001 when I wanted to buy a metronome. But I could not find anything satisfactory. Cheap metronomes were only quietly beeping and the volume could not be set. And good metronomes were too expensive. I wanted accurate frequency, possibility to tune, long battery life and with nice click sound with adjustable volume.

My first attempts to build a metronome were very simple and did not satisfy me. The frequency was dependent on a variable RC circuit, which was not calibrated. I stopped a development for a some time. A year later I found nice circuit on internet with crystal-based metronome. You can see it here. The problem was, that it did not work at all. I tried to analyse the circuit and I did not understand how it could work to anybody.

I did not give up. I was inspirated by this circuit and I started developing my own metronome. The block scheme is the same but individual blocks are completely changed. That is how the first version of my crystal metronome was borned. There was a transistor in the output part of circuit and it was not good. I did not like the sound. That is why I started developing the second and final version within the scope of one school subject. After the consultation with my teacher I used two 555 circuits which generate nice and loud click which we know from original mechanical metronomes. I made a printed circuit design in Corel Draw and I built the metronome. I put it into a box from antiallergic vaccine and it perfectly fit in. I use the metronome till today and only few little repairs were needed.

Download scheme and printed circuit. Sorry, the description is in Czech language only.