Power
Regulators, protection and supply circuits that keep the rest of a project alive.
11 builds
VideoHow your ESP32 reads a 12V battery: the voltage divider
Two resistors scale a 12V battery down to a voltage an ESP32's 3.3V input can read safely, with a zener as a backstop.
6 parts · 9 wires
PowerSensors
VideoThis LED tells you how dead your battery is
A light for a 12V lead acid battery: green when it's healthy, yellow when it's getting low, red when it's nearly flat.
13 parts · 17 wires
PowerTools and test
VideoThis lights an LED from a dead battery
One transistor and a hand wound coil that light a white LED from a nearly dead 1V cell. Six parts.
6 parts · 9 wires
LightsPower
VideoAn H-bridge with no chip
Four transistors and four diodes that drive a DC motor either way from two control inputs. No driver chip.
12 parts · 16 wires
Power
VideoWhy the most-built circuit gets hot (the math)
A 7805 taking 12V down to 5V, and the one line of math that tells you whether it needs a heatsink.
8 parts · 10 wires
Power
VideoOne knob dims a 12V LED strip. No code.
One knob dims a 12V LED strip. A 555 timer makes the PWM and a MOSFET switches the strip. No microcontroller, no code.
12 parts · 22 wires
LightsPower
VideoThe most-built circuit in electronics
A 7805 regulator board: 7 to 12 volts in from a barrel jack, a steady 5 volts out, and an LED that shows it's on.
10 parts · 7 wires
Power
Premieres Oct 23One part saves your board when you plug it in backwards
One P channel MOSFET that passes power with almost no loss when you plug in the right way, and blocks it when you don't.
7 parts · 7 wires
Power
Premieres Nov 12The circuit inside every relay module
The small circuit inside every hobby relay module: a transistor switch, a base resistor, a flyback diode and a status LED.
7 parts · 9 wires
Power
Premieres Nov 22The regulator every ESP32 secretly needs
A 3.3V supply for an ESP32: an LD1117 regulator with enough capacitance to ride out the radio's current spikes, plus a power LED.
8 parts · 12 wires
Power
Premieres Nov 25The emergency light that turns on when the power dies
Three white LEDs that switch on from a battery the moment the wall adapter loses power, and charge it while it's plugged in.
14 parts · 5 wires
LightsPower
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