Keeping signal OR not letting signal float

[woodturner550]

I am working on a project that has two IR sensors that will turn high when triggered. They go low when the trigger is removed. I will be using one for each end of the movement of the DC motor.

What I need is for the one to drive the signal high and hold it high and the other to drive the signal low and stay low. I guess on one I would use a flip flop to get the low signal.

How do I keep the signal high till the next signal is sent?

woodturner550

 

[lilimike]

An inverter?

Edit: no good, that would only work one way.

Mike

 

[Reloadron]

You could likely use a D flip flop like the 74HCT74 (or similar FF). The data sheet can be found here. You could configure it similar to what you see here.

You would use your sensors to toggle the Set and Clear inputs to the chip. I am sure other flip flops could be used as well or the same flip flop in other configurations.

Ron

 

[Mike_2545]

I was thinking of SCR

 

[woodturner550]

Thanks for the ideas and giving me a direction I should be exploring.

woodturner550

 

[crutschow]

I was thinking of SCR

An SCR will stay on after it's triggered until the current flowing from the anode to cathode is stopped. That's not readily done in his circuit. SCRs are usually used in AC circuits where the current normally goes through zero each half cycle and resets the SCR.