Hello,
Thanks. So I went thru it, but in this desing we cant use usb charger + battery?

Yes we will, with a 3.7v -> 5v boost module too. I just didn't show that.

 

Here you go....

With all due respect here's a simpler version.
Delay appx 20 seconds max with RV1 at 1M.
In this configuration output pin1 of the LM393 is Low in the standby mode.
When the input goes to 0V the output goes High and the delay timer starts.

 

Won't work. The pull-up on the HZ inputs is about 100k, so the opto's LED will be seen as a short by comparison. Anyway a 1Mohm series resistor on the 3v across the HZ terminals won't register on the opto - it needs at least a couple of mA....

 

According to the TS there is 30VDC across HZ1 and HZ2.
With the opto completely isolating the two circuits why would the output only be 3V?
With 30VDC input on the opto the voltage across R2 is 2.1 volts, verified.

 

No, 30v is acros BUS terminals. HZ terminals are floating and pulled up to 3.3v which drops to 2.9v with a 1Mohm test meter, hence 100k internal pull-up.

 

No, 30v is acros BUS terminals. HZ terminals are floating and pulled up to 3.3v which drops to 2.9v with a 1Mohm test meter, hence 100k internal pull-up.

In that case back to version #1:

 

Hello,
Thank you


So which version should i try? Thx

 

Hello,
Thank you


So which version should i try? Thx

Post #126

 

So which version should i try? Thx

Here's Version #2 if you prefer to use one of those 5V relay modules.

 

Post #126

That works well, with following minor changes: Add new resistor (now R7) between RV1 and 5v rail (prevents shorting U1A output to 5v and gives more useful delay range). Change value of R8 (was R7) from 100k to 10k (more stable operation).

 

thanks,
Can i use also sb160 instead of sb130?
and also for a what level to set RV1?
also can use STMicroelectronics LM393D?

thanks

 

thanks,
Can i use also sb160 instead of sb130?
and also for a what level to set RV1?
also can use STMicroelectronics LM393D?

thanks

Set RV1 in the middle for now.
SB160 and LM393D both OK.

 

will try,
that relay module is fine? its state in its spec 5V, low trigger

 

will try,
that relay module is fine? its state in its spec 5V, low trigger

Which relay module is that?
Use this circuit with a Low input relay module:
With RV1 at midway gives appx a 20 second delay.

 

@sghioto its that one

 

@sghioto so is that module okay? thx

 

@sghioto so is that module okay? thx

Sure, just make sure to set the green jumper to "L".