# transistor as switch for 2 condition

Discussion in 'The Projects Forum' started by embpic, May 19, 2014.

1. ### embpic Thread Starter Member

May 29, 2013
187
3
i need a logic using transistor (as a switch) for 1 input and 2 output. if i provide input of 5 volt then one end should be 5 volt and other end should be 0 volt.
likewise when input is 0 volt then one should be zero ande other will be 5 volt.

i think 2 transistor are require one is NPN and other one is PNP.

2. ### DickCappels Moderator

Aug 21, 2008
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If I understand your requirement, the circuit below should do what you want. More details would be helpful.

djsfantasi likes this.

Mar 14, 2008
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4. ### embpic Thread Starter Member

May 29, 2013
187
3
output is one stepper driver and my condition are as follows.

input output1 output2
1 5 Volt 0 Volt
0 0 Volt 5 Volt

5. ### embpic Thread Starter Member

May 29, 2013
187
3
input output1 output2
1 5 Volt 0 Volt
0 0 Volt 5 Volt

6. ### djsfantasi AAC Fanatic!

Apr 11, 2010
3,496
1,253
DickCappels provided a simple circuit, and he asked for details of the load. I am also curious as to what is providing the input. You did state that a logic 1 is 5V and a logic 0 is 0V.

If you can drive a load from your input, his circuit is the simplest that I can imagine. Check it with your truth table and confirm for yourself that it works.

If you cannot drive the load directly from your input (hence Dick's circuit may not work), you can add another transistor for the second output. I have tested in a simulator the following circuit. Note that both transistors are of type NPN. The values shown are simply for the simulation and would need to be calculated for your specific application.

The first NPN transistor inverts the input, while driving the second transistor and the load. The second transistor then inverts the signal once again and drives the second load. If you examine your truth table, this satisfies your conditions. Note that "output 1" follows the input and "output 2" is the inverse of the input.

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(The second attachment shows the logic in the opposite state)

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7. ### DickCappels Moderator

Aug 21, 2008
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Please post a description, datasheet, or part number and manufacturer for your stepper motor when you post your description of the signal source.

8. ### embpic Thread Starter Member

May 29, 2013
187
3
Thank you sir i have done i will post schematic soon.....