For the airsoft gun I have equipped to my robot, I need to add a 5v regulator to a 7.2V power supply. I am using this becuase regular batteries run out in about 10 minutes. Will a skotchy diode suffice?
thanks,
I would go with something like this to have a nice 5V continuosly :
POWER-------------RESITOR
kkkkkkkkkkkkkkkkk|
kkkkkkkkkkkkkkkkk|-----------------POWER (should have 5V)
kkkkkkkkkkkkkkkkk|
GROUND--------ZENER DIODE
kkkkkkkkkkkkkkkkk|-----------------GROUND
modify the the resistor/diode to get the voltage you need.
P.S. ignore the K’s, I had to change the line of place and didn’t seem to work with spaces… 
You may need to explain a little better what you are trying to do or issue you are trying to solve.
Sorry, this topic is kind of a waste. I created a simple 5v regulator to solve the problem (similar to Sam’s post). I was just asking if the diode I had would work.
Thanks anyways.
Italian_guy299,
If you really want to conserve battery life, then you need to use a 5vdc switching regulator with an efficiency of around 80% or higher.
A zener diode regulator is a very inefficient method of voltage regulation and wastes a lot of power.
If you do not want to incorporate a 5vdc switching regulator (BEC) I would at least use a LM7805 linear regulator with a good heat sink.
Just a thought.
Regards,
TCIII
The 5v regulator I built now was just to test the gun mech of my robot and is temporary since I don’t have a 5v batt @ hand. I will be using this one after I order it:
If what you are doing is to power the gun, you probably are getting ready to waste some $$$. Since the gun probably only operates only in 2-3 second burst, you probably could directly power it from the 7.2v battery (it normally operates at ~6v from four 1.5v alkline batterys). To drop the voltage some if desired, get a rectifier diode at radio shack and put it in series between the 7.2v battery and the gun to drop the voltage to 6.5v. It may not work as well if operated a 5v.
Ya, I took off the regulator and just powered it directly from the 7.2v battery since it will only be turned on for 2-3 seconds of operational bursts. I also like the way the gun shoots slightly faster now like a real fully automatic gun since the upgrade of the beefier battery.
Just use the code box. It uses monospaced fonts.
POWER-------------RESITOR
|
|-----------------POWER (should have 5V)
|
GROUND--------ZENER DIODE
|-----------------GROUND
Um, not sure if this was what you were looking for…
ahh, Thks!
Well now I’ll know how to do it!
That setup is because my chip could only take 5 volts, so I didn’t really mind using up my 9V batery up for that. Power consumption is much more important on robots.