Normally Close Switch Circuit

[E_B]

Hello
First of all, pardon me for my weakness in English.

I need to use two kind of normally closed switch circuits that work with about 18v dc.
One of them, output the voltage if the input is float or GND(0v), like the picture.



But the other one has to output the voltage when the input is float or Voltage(18v).
Plus, it is important that the type of the circuits must not be recognizable by sensing the inputs with any instrument.

Unfortunately I can't design the second one.
Could you help me please!

 

[dr pepper]

If I understand your question correctly, all you need to do is put the resistor connected to the emitter in the collector circuit and take your gate drive from the collector.

 

[E_B]

thanks dr pepper

current circuit acts like this:
input output
0 ---> 1
float ---> 1

1 ----> 0


but I need a circuit to do this:
input output
0 ---> 0

float ---> 1
1 ---> 1