Tuning Fork Oscillator

[BillC]

Have been trying to make the triple fork design but it has proved to be too difficult to cut out from the old saw blade stock, difficult to work out where to place the cuts. So I have gone for the simpler twin tyne fork. The fork in the image vibrates at a frequency of 1248 Hz at around 10 degrees C. The frequency was found by zero beating the fork to a known source. At this stage I plan to drive the fork using relay electromagnets. And could use my audio spectrum sweeper to check the results, in the range 200Hz to 4KHz, we will see what happens..

 

[VK3YNV]

Nice bit of gear, and an interesting project. I saw tuning forks ebay, but they were all two prong, not the three prong version you were looking for..

 

[BillC]

Hi Ray, thanks for the comments it is all very interesting . The fork vibrates very well at its frequency. I used a small 24 volt relay coil as the driver with its pole piece driving one leg of the fork, best activity about half way along and coupled within a few thou''. The impedance of the driver coil is 673.6 mH. as measured. Am using the generator of the test set to power the fork driver coil, but I think the driver needs more power. More experimentation needed, lots more fun to be had.. Cheers.