Buffer In Between Switches for Logic circuits

[danny davis]

What kind of buffers or What analog logic chips can I use as buffer to put in between a Double or single throw switch to a Logic Circuit?

The Double Pole switch is going to switch from -10 volts to + 18 volts , but I need a buffer in between the switch to the logic circuit

Double pole switch ---> Buffer chip ----> Logic Circuit

My Manager said I need a buffer chip in between switches to logic circuit because from switching it can cause damage to the Logic circuit while switching, so the buffer chip protects it

 

[IanP]

What kind of buffers or What analog logic chips can I use as buffer to put in between a Double or single throw switch to a Logic Circuit?

The Double Pole switch is going to switch from -10 volts to + 18 volts , but I need a buffer in between the switch to the logic circuit

Double pole switch ---> Buffer chip ----> Logic Circuit

My Manager said I need a buffer chip in between switches to logic circuit because from switching it can cause damage to the Logic circuit while switching, so the buffer chip protects it

The simplest buffer circuit is just a single resistor and a Zener Diode, see attached picture ...
Other options: single transistor Open-Collector configuration, optocoupler, etc. etc.
:wink:
IanP

 

[danny davis]

Any reason why I need a buffer? for what reason? why not go direct without a buffer?

 

[IanP]

Any reason why I need a buffer? for what reason? why not go direct without a buffer?

Danny, you don't need a buffer, all what you need is to protect the input against out-of-range signals.
In case of logic circuits, the input usually takes signals between GND (0V) and Vcc (3V, 5V ....) ..

:wink:
IanP

 

[danny davis]

So a series resistor and zener diode would be best to be the buffer than?

The zener diode would Clamp the voltage to be safe

 

[IanP]

So a series resistor and zener diode would be best to be the buffer than?

The zener diode would Clamp the voltage to be safe

Resistor + zener, or resistor + 2 signal diodes (see attched picture) is the way to go ...
:wink:
IanP