1, 2, 4, 8 pulse count generator

[StefanV]

I build a simple type of skee-ball game. A wooden ball is rolled into 1 of 4 holes, a switch triggers a pulse generator, it steers a score counter.
My breed board version has quite a few 555's, 74121's and 7400's to generate a train of either 1, 2, 4 or 8 pulses that I can feed the score counter. This way you can see the score add up in steps of 10 (I added a fake 0 at the end). But timing is difficult, as my 8 count pulse train turns out 9 sometimes. (74121 one-shot steering a 555 timer)
Does anyone have a good idea or a schematic for a simple setup that will give me a TTL output of 1, 2, 4, or 8 pulses depending on the triggered switch?<p>Thanks! Stefan V.

[dyarker]

A 74191 set to count down.<p>Each switch (1 2 4 to pre-load a stage of '191.<p>555 set to free run (oscillate). 555 output is your pulses and clk for '191.<p>gate the outputs of '191 so that when all are zero the 555 is stopped. if ANY stage of '191 is one, the 555 runs.<p>the '121 might still be needed to de-bounce the switches.<p>Cheers,

[StefanV]

Thanks! I got a 74191 here, let me get back to my breed board.
Stefan

[Chris Smith]

4017 divide by 10?