Looking for a component to switch between GND and floating

Thread Starter

Stolco

Joined Jan 21, 2020
2
Hello,
I'm looking for a component which allows me to switch the output between GND and floating, as shown in the image below. When the trigger is logical 'high' the output should be connected to the floating contact (see 1), so that it's not absolutely zero. When the trigger is logical 'low' the output should be connected to the GND (see 2). The 'output' signal is used for triggering. I have to pull this pin to GND to trigger the device, but I am not allowed to pull it to 3v3 afterwards. That's why I want to let it float before triggering it again. I've tried above with a optocoupler and a transistor, but this didn't work. I except this is because of the threshold of about 0.7V of a transistor.
Does anyone have an idea what's the best fitting solution for my problem?

Drawing switch.png

Kind regards,
Stolco
 

wayneh

Joined Sep 9, 2010
16,402
The open-collector output pin of a comparator might be close. You have to pull it high if you want it to go there. If you don't, it's "floating".
 

Thread Starter

Stolco

Joined Jan 21, 2020
2
First of all, thanks for all your good suggestions!

hi Stolco,
Welcome to AAC.
Perhaps a CMOS device of this type would be suitable.
E
View attachment 197351
This looks like the most simple solution and is exactly what I need, so I will try this first. Thank you.

The seller of this device describes it is not allowed to pull power on the trigger pin of this device. Otherwise the device would break, according to the seller.
 

wayneh

Joined Sep 9, 2010
16,402
The seller of this device describes it is not allowed to pull power on the trigger pin of this device. Otherwise the device would break, according to the seller.
That's lame. He should specify a limit in terms of current or load impedance. For instance I doubt that the megohm impedance of an op-amp would "break" his device.
 
Top