Ohms Law Wheel
Voltage (V) Current (I) Ohms (R) Power (W)
LED with Resistor
Supply Voltage Volts
Diode Forward Voltage Volts
Diode Current milliamps (mA)
Calculated Resistance Ohms
Next Standard Resistor Ohms
Resistor Power milliwatts (mW)
Zener Regulator
Vi: Enter source voltage
(must be at least 2V higher than desired output.)
Vo: Enter desired output voltage (zener voltage)
Iq: Enter load current in mA.
Add 10% to be on safe side.
Prefered Zener value: V
Zener diode power rating: mW
Select a zener diode with a higher rating than the value above
Resistor value: Ohms
Prefered Resistor value: Ohms
Select a resistor with a value as close as possible to the value above
a little below is better than a little above.
Resistor power rating: mW
Select a resistor with a power rating higher than the value above.
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