Re: [CAD_CAM_EDM_DRO] Need Encoder Hookup Help

Bob Bachman wrote:

> OK you techy types, help me out.
>
> I have a coule of Red Lion counters which will make dandy readouts
> for a DRO. I also have some of the famous Goldmine motors with attached
> encoders.
>
> The problem: The encoders are 5 volts and the counters are 12 volts.
> The 5 volt outputs from the encoder will not trigger the 12 volt logic
> of the counter. I need a simple circuit that will use the 5v pulses
> from the encoder to create 12v pulses for the counter.

There are a couple of ways to do this. One way is with some
NPN transistors, like 2N2222. Connect the encoder output to a
10 K resistor, the other end of the resistor to the base of the
transistor. the emitter goes to ground. The collector has a 3.3K
resistor to +12 v from the counter, and also is connected to
the counter's input.

Another way is with a CD4049, from the 12 V CMOS series. If you
take the encoder output through a 5K resistor and to the input
of the CD4049, and also have a 10K resistor to +12 at the input
to the chip, it will shift the logic levels up so they cross the 6 V
threshold of the CD4049, which needs to run off the 12 V supply
from the counter. The CD4049 output will be a 0 to 12 V
signal.

Jon