Product Review

2 Pack
555 Timer modules make it simple to connect, adjust, and experiment with these versatile ICs.

The jumpers select frequency bands - J1 being the lowest and J1 being the highest. The two pots control frequency and duty cycle (though these are not intependent) so the adjustment of these pots determines the actual output frequency within the selected band.

The maximum frequency we have measured (with a Saleae logic analyzer) is ~302kHz, and the minimum around 0.56Hz (this depends on how light of a touch you have when turning the pots).

These measurements were taken @ 5V supply voltage