Zener Diode Voltage Regulator: Circuit, Measurements and Online Simulator

To build this Zener Diode Voltage Regulator circuit you need a bench power supply, a digital multimeter, a 15 V analog voltmeter, a 470 Ω resistor, a 5.1 V Zener diode and a 2.2 kΩ resistor. A 5.1 V Zener with a 470 Ω series resistor holds its output steady while you turn the bench supply from 6 V to 15 V. Make the 10 connections in the wiring table, press Run, and and turn the supply's VOLTAGE knob: the multimeter stays near 5.1 V while the analog voltmeter across the resistor takes up the difference.

Open this circuit in the free Electronics bench simulator

Parts list

Qty	Part	What it does
1	Bench Power Supply	Set the voltage and a current limit. It holds the voltage (CV) until the load wants more than the limit, then holds the current (CC). + and − float; GND is earth.
1	Digital Multimeter	Turn the dial: V (across a part, COM and V), A (in series, COM and A), Ω / continuity / diode (on an unpowered part), Hz. The A range has a 10 A fuse — put it across a supply and it blows.
1	15 V analog voltmeter	A moving-coil panel meter (20 kΩ/V): wire it across the voltage, + to the higher side. The needle has real inertia.
1	470 Ω resistor	Limits current. 220 Ω in series with an LED; 10 kΩ as a pull-up or pull-down.
1	5.1 V Zener diode	Conducts forward like a diode; reversed, it holds its Zener voltage — a simple regulator with a series resistor. The stripe is K.
1	2.2 kΩ resistor	Limits current. 220 Ω in series with an LED; 10 kΩ as a pull-up or pull-down.

Wiring

#	From	To
1	Bench Power Supply +	470 Ω resistor leg 1
2	470 Ω resistor leg 2	5.1 V Zener diode K
3	5.1 V Zener diode A	Bench Power Supply -
4	470 Ω resistor leg 2	2.2 kΩ resistor leg 1
5	2.2 kΩ resistor leg 2	Bench Power Supply -
6	Bench Power Supply -	Bench Power Supply GND
7	470 Ω resistor leg 2	Digital Multimeter V
8	Bench Power Supply -	Digital Multimeter COM
9	470 Ω resistor leg 1	15 V analog voltmeter +
10	470 Ω resistor leg 2	15 V analog voltmeter -

Step by step

Open the electronics bench. Open the BitForBytes Embedded Lab in your browser. A circuit with no microcontroller runs on the analog bench: no install or account is needed.
Add the parts. Add a bench power supply, a digital multimeter, a 15 V analog voltmeter, a 470 Ω resistor, a 5.1 V Zener diode and a 2.2 kΩ resistor from the parts palette (Instruments, Power, Passive and Semiconductors).
Wire 1. Connect Bench Power Supply + to 470 Ω resistor leg 1.
Wire 2. Connect 470 Ω resistor leg 2 to 5.1 V Zener diode K.
Wire 3. Connect 5.1 V Zener diode A to Bench Power Supply -.
Wire 4. Connect 470 Ω resistor leg 2 to 2.2 kΩ resistor leg 1.
Wire 5. Connect 2.2 kΩ resistor leg 2 to Bench Power Supply -.
Wire 6. Connect Bench Power Supply - to Bench Power Supply GND.
Wire 7. Connect 470 Ω resistor leg 2 to Digital Multimeter V.
Wire 8. Connect Bench Power Supply - to Digital Multimeter COM.
Wire 9. Connect 470 Ω resistor leg 1 to 15 V analog voltmeter +.
Wire 10. Connect 470 Ω resistor leg 2 to 15 V analog voltmeter -.
Run and measure. Press Run and turn the supply's VOLTAGE knob: the multimeter stays near 5.1 V while the analog voltmeter across the resistor takes up the difference.

Lab sheet

// Electronics bench: Zener regulator
//
// Supply → 470 Ω → node → Zener (cathode to the node) → 0 V, with a 2.2 kΩ load.
// Above 5.1 V the Zener conducts in reverse and holds the node there;
// the resistor drops everything else: V(R) = Vsupply − 5.1 V.

What to try

Press Run and turn the supply's VOLTAGE knob: the multimeter stays near 5.1 V while the analog voltmeter across the resistor takes up the difference.

Frequently asked questions

How do I wire the Zener Diode Voltage Regulator circuit?

Make 10 connections: Bench Power Supply + to 470 Ω resistor leg 1; 470 Ω resistor leg 2 to 5.1 V Zener diode K; 5.1 V Zener diode A to Bench Power Supply -; 470 Ω resistor leg 2 to 2.2 kΩ resistor leg 1; 2.2 kΩ resistor leg 2 to Bench Power Supply -; Bench Power Supply - to Bench Power Supply GND; 470 Ω resistor leg 2 to Digital Multimeter V; Bench Power Supply - to Digital Multimeter COM; 470 Ω resistor leg 1 to 15 V analog voltmeter +; 470 Ω resistor leg 2 to 15 V analog voltmeter -.

What parts do I need for the Zener Diode Voltage Regulator?

A bench power supply, a digital multimeter, a 15 V analog voltmeter, a 470 Ω resistor, a 5.1 V Zener diode and a 2.2 kΩ resistor.

Can I simulate the Zener Diode Voltage Regulator online for free?

Yes. The BitForBytes Embedded Lab solves the circuit in time, the way SPICE does (nodal analysis with real diode, transistor and capacitor models), and gives you a bench power supply, function generator, oscilloscope and multimeter to measure it — free, in the browser.

What does this circuit show?

A 5.1 V Zener with a 470 Ω series resistor holds its output steady while you turn the bench supply from 6 V to 15 V.