Please sghioto ; can you help me to adapter your schematic on my real application?

Is this what you mean?

 

Hello everyone and thanks

Inside the package are four SPST normall-open switches. You new two enable signals, one for each switch. It is possible to use one switch as an inverter to make an enable signal that does the opposite of the original enable signal. If your load(s) are not high impedance you can use and opamp voltage follower as a buffer.

Maybe I missed it but is there any reason you can't use small relays with silver or gold plated contacts? This would reduce any loss through semiconductor devices. Relays with very low coil currents.

Thanks DickCappels and Reloadron

I am a beginner in electronics; I have difficulty understanding the transistors which are the base of electronic, so I have to do it with transistor before any other monolithic IC

Is this what you mean?

So please, if you can?

I need two things:

Explain to me your circuit to understand why it works

Help me to Adapter it on my real application



1 - I have V_ref connected directly to the inverting pin (-) of the operational amplifiers which is used as comparators, this V_ref is changed voltage

2- I have (Vref02 / Vref01) connected both to the non- inverting pin (+), those references must be fixed voltage

3- EDIT : Another thing please can you do it with small resistors about 5 or 6 kΩ the biggest one instead of 100 kΩ

This HIGH or low output from the Op – Amp determine which one of the two (Vref02 / Vref01) is commuted only one in time.
High for Vref01 and low for Vref02, this is simple in the case of the Vref02 transistor (low), but when get high sometimes I have the biasing of the tow transistors on the same time

So please excuse me if the way I expressed it was not clear.

 

but when get high sometimes I have the biasing of the two transistors on the same time

That may happen if the supply voltage for the LM324 is less than the Vref02.
What is the supply voltage for the LM324?

3- EDIT : Another thing please can you do it with small resistors about 5 or 6 kΩ the biggest one instead of 100 kΩ

Why is that?

 

Hello and thanks

“”But when get high sometimes I have the biasing of the two transistors on the same time””

No here I am speaking about my circuit not your’s

All what I need now


Explain to me your circuit to understand why it works

Help me to Adapter it on my real application

The supply voltage for lm324n is +12v

“”EDIT : Another thing please can you do it with small resistors about 5 or 6 kΩ the biggest one instead of 100 kΩ””

(I have only small resistors)

and I thought when I reduce the current for all entire circuit from the beginning this will not cause problem

So if you can do it with small resistors about 5 or 6 kΩ this will be good

and if not , I am saying that you know what are doing

And again, please excuse me if the way I expressed it was not clear.

 

Explain to me your circuit to understand why it works

When the output of U1A is high D1 and Q3 are reversed bias. This allows Q1 to turn ON by the V_ref_01 voltage.
At the same time, Q2 is switched ON by Q1 which passes the V_ref_01 voltage to the output.
When the output of U1A is low Q3 switches ON and passes the V_ref_02 to the output.
At the same time D1 is now forward biased and shuts OFF Q1.
You can change all the resistors to 5 or 6K with no problem as long as this does not effect the value of those reference voltages, V_ref_01 and 02.

 

thanks sghioto , i will try the circuit on the #21 post and if i get any problems i will tell you as soon as possible