I recently purchased a "Canakit" Mini Electronic Timer I want to install on my motorcycle. Instructions indicate I can use 9 or 12 volt input. I would like to just use the MC 12v system but, of course, the voltage can go up to around 13.5
There are few components on the board and I guess the one I would have to worry about is the 555 timer. When they say "12 volts" do the really mean it or could I just go ahead and hook it up to my MC electrical system?

Can you see the actual chip number on the 555 timer? There are different ones, but I believe most can go up to 18V MAX (don't want to run it there all the time). But if this is a device designed for automotive "harshness", you should be fine.

Although not sure I'd hook a 555 timer directly to an auto application without some kind of regulation or filtering at a minimum.

I just looked up that device you have. What is the full chip text and what voltage are the capacitors rated at?

If you're concerned and your circuit won't be drawing much current a crude solution would be to add two diodes in series with the power connection.

Originally Posted by Sceadwian

If 2 extra volts causes a failure in the discrete components on the circuit board the engineer that designed it should be dragged out and shot.

Transients on auto/MC electrics can easily hit 50+ volts for brief periods but long enough to do damage.

for automotive applications.
here is an adjustable one for 3 - 20 v
they do have non adjustable ones as well
National Semiconductor - LM2941S/NOPB - Allied Electronics

Originally Posted by MrDEB

for automotive applications.
here is an adjustable one for 3 - 20 v
they do have non adjustable ones as well
National Semiconductor - LM2941S/NOPB - Allied Electronics

The lm2940/1 do have built in surge protection up to 60V specifically for automotive applications. They are generally junky parts, but they will survive in auto electrics better than most ICs because of that.

Thanks much for all the responses...
As you can tell by my question I am just a hack at this stuff but, armed with the information you have provided, I have an idea on how to proceed. Today I drew up a circuit and will try and build it. When I (1) am successful or (2) have to admit to utter defeat I will post results.

Originally Posted by fatfenders

Thanks much for all the responses...
As you can tell by my question I am just a hack at this stuff but, armed with the information you have provided, I have an idea on how to proceed. Today I drew up a circuit and will try and build it. When I (1) am successful or (2) have to admit to utter defeat I will post results.

If you can define the exact function you need the timer to do, there are probably lots of circuits out there already canned up. I use 555's for the turn signal flasher on my bike right now.

If voltage goes beyond prescribed level then a number of components are available.One can go for zener(Vz=12v) or you may go for 7812(voltage regulator.)