Regulate a voltage
Pin a messy or higher voltage to a clean 5 V or 3.3 V.
need a regulator (7805 / a buck module) · caps
do feed it in, get a steady rail out.
Every project on the shelf needs it, and this is the issue where the bench can actually bite back. Sources, regulators, batteries, and caps — how to feed a circuit cleanly, and how not to start a fire doing it.
Portable chemical storage — alkaline, NiMH, Li-ion/LiPo, coin. The on-the-go default.
portableA "wall wart" or bench supply turns mains into clean low-voltage DC.
from the wallTurns a higher or messy voltage into a fixed, steady rail.
cleans it upPanels and tiny harvesters scavenge power from light.
harvestShort-term storage — smooths supplies and delivers bursts.
smooth & burstCircuits that charge cells safely and protect them from abuse.
safe chargePin a messy or higher voltage to a clean 5 V or 3.3 V.
need a regulator (7805 / a buck module) · caps
do feed it in, get a steady rail out.
Boost one cell to 5 V, or buck 12 V down — efficiently.
need a buck / boost converter
do set the output; switching converters waste little as heat.
Pull stable 5 V from a port or power bank.
need a USB breakout · your circuit
do tap V+ and ground; many projects run straight off it.
A dead PC supply becomes a multi-rail bench supply.
need an old ATX PSU · a load resistor · binding posts
do jump it on; tap the 3.3, 5, and 12 V rails.
⚠ caps inside — dischargeMatch chemistry and voltage to the job.
need alkaline / NiMH / Li-ion / coin
do weigh capacity, rechargeability, size, and safety.
Cells in series for volts, parallel for capacity.
need matched cells · a holder
do series adds voltage, parallel adds run-time; keep them balanced.
A proper charger tops up lithium without drama.
need a TP4056-style charger · protection
do charge attended; never bodge a lithium charger.
⚠ lithiumRead the voltage to estimate charge, and cut off when low.
need a divider into an ADC
do map voltage to %; shut down before over-discharge.
A cap across the rails kills noise and dips.
need a capacitor near each chip
do decouple every power pin — cheapest reliability there is.
A big cap dumps power faster than any battery — a camera flash is exactly this.
need a large capacitor · a fast switch
do charge slow, release fast.
⚠ stores a real joltRide through a brief power loss.
need a supercapacitor
do keep a clock or RAM alive across a blink of the supply.
A tidy power-on, or a one-touch latching button.
need an RC delay or a soft-latch circuit
do ramp in gently, or toggle power with a tap.
A panel tops up a battery through a controller.
need a solar panel · a charge controller · a cell
do let the controller manage it — don't wire a panel straight to a cell.
A motor-generator (see no. 2) charges a cell or cap.
need a DC motor · a diode · storage
do spin it, rectify the output, store the energy.
Reuse a power bank's cell and charger board.
need a USB power bank
do harvest the protected cell + boost board as a tidy supply.
⚠ lithiumKeep a backup cell quietly topped up.
need a small source · a charge circuit
do float-charge so it's ready when the main supply drops.
A multimeter is the one tool you can't skip.
need a multimeter
do read volts, check current, test continuity — before you trust anything.
Add up what every part pulls at peak.
need each part's draw · arithmetic
do size the supply with headroom; a starved rail browns out.
Cheap insurance against smoke and reverse wiring.
need a fuse · a series diode or P-MOSFET · maybe a TVS
do fuse the pack, block reverse polarity, clamp the spikes.
One reference, wire thick enough for the current.
need solid grounds · the right gauge
do tie all grounds together; short, fat runs for high current.
workbench series · volts push, amps flow, watts cost · respect lithium and the wall