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Old 01-10-2021, 07:05 AM   #1
barry wilkins
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Join Date: Aug 2009
City & State: Maidstone Kent
Posts: 164
Default 4017 counter reset problem

I have been trying to make a counter for my vehicle alarm .I need to reduce the pulses that operate the hazard warning lights.
Because of the ECU you cannot connect directly to the lamps ,so I fitted a relay across the hazard switch. This works ,but because the number of pulses are odd this causes the lamps stay on ,and you have to switch them off by pushing the switch once.
I had a couple of ideas ,one was to use a couple of 74121 monostable ICs to give me 2 pulses.
The circuit I came up with is a Decade counter that uses counts 0 and 3 summing these together gives me the 2 pulses I need if I feed back count 4 or 5 as a reset
Occasionaly the second pulse returns to a high causing the relay to stay on, ,it seems like the reset might the the problem .
On the TI data sheet it does show a circuit using a 4001 to reset the IC.
Any thought on how I could solve this ?

Barry Wilkins
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