CD4049 momentary to latching - power up in known state?

Started by composition4, October 25, 2017, 11:49:32 AM

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composition4

Hi all,

Possibly a simple one.. is there any way to make an inverter-based latch such as this one from RG's site power up in a known state?

I'm thinking I may be able to achieve it by holding a pin high with a cap on power-up or somethuing similar but can't get my head around it at the moment.



Thanks!

Jonathan

marcelomd

A few weeks ago I was looking for something similar and found this:

https://electronics.stackexchange.com/questions/186841/momentary-button-as-switch

The first answer explains how to do it. They used it for controlling a PC power supply, but the theory is the same.

In the end I used the circuit you posted as it always powered up the way I wanted. I had to play with the resistor values a bit to reduce bouncing. 

marcelomd


composition4