SensingBench electronicsHand tools, works as-is

Infrared remote receiver

Also called TSOP, VS1838, IR demodulator.

The three-pin can in the corner of a TV, a set-top box, a DVD player, or a soundbar. It already demodulates the 38 kHz carrier. The output is a logic pulse train, active low, not a raw photodiode.

If you are new to this category

A sensor reports a condition such as weight, light, temperature, or position. Many sensors do not switch fully on or off. A kitchen scale bar, for example, changes by thousandths of a volt. Keep the small board that read the sensor if you still have it.

Keep the connector. Write down the wire colors before you cut them. If you do not know which wire is which, the sensor is hard to reuse.

Four wires on a scale sensor

Red and black feed the sensor a steady few volts. Green and white are the tiny signal, measured between them, not from either one to ground. Pressing the bar changes that signal by millivolts. A normal meter on DC volts can show that it responds. Turning it into a number on a screen wants a small amplifier board, often an HX711.

Specification. The right-hand column is what is typical. The label on the part in your hand wins if they disagree.
What to look for	Usual figure
Pins	Usually OUT, GND, VCC. The order is not identical on every clone. 1838-class is OUT, GND, VCC looking at the lens with pins down.
Supply	3.3–5 V. A 100 µF capacitor at the pins saves you from false pulses.
Carrier	38 kHz is the usual consumer remote. Some gear uses 36 or 40. A mismatch reduces range rather than silence.

Volts are electrical pressure, amps are how much current is flowing, and ohms are how hard the part resists that flow. A higher voltage than the part was built for is how salvage parts die on the bench. If a cell in the table says “read the stamp”, that stamp is the whole specification.

What people actually use it for

Any project that should obey an existing remote
A beam-break only if you modulate the transmitter at the carrier. An unmodulated LED will not trigger it.

Leave this one when

The lens is cracked or it was desoldered with no idea which pin is VCC. Trying 12 V 'to be sure' kills it.

Buying a new one is the better idea when

A new VS1838B when you need the pinout in writing. Salvage is for the one still on its little board with the connector.

How to tell if this one still works

5 V and ground, scope or a microcontroller on the output, press a remote at it. Pulses should appear.

Tools you will want: 5 V, A remote, Logic pin or scope.

Words on this page

Short meanings, so the rest of the entry is readable if you are not already doing this every weekend.

capacitor: A part that stores a small amount of electrical energy. Large ones in power supplies can stay charged after you unplug. Discharge them before you touch the leads.

Where people actually find it

3 notes, most useful first. “Leave it” means the part is in that machine and you should not take it: it is dangerous, worn out, or only useful if you already know that exact repair.

Harvest at a glance
From	Call	How many	How often	Where it sits
Set-top box or streamer	Prize	1	usually	Front panel.
LCD television	Prize	1	usually	Front bezel, often a separate board.
DVD or Blu-ray player	Prize	1	usually	Front panel.

Prize — take this firstSet-top box or streamer1 · usually
In this particular machine
A three-pin demodulating receiver, often still on a handy little board.
Where to look
Front panel.
How to get it out
Keep the board and the connector.
The condition to expect
Good.
Prize — take this firstLCD television1 · usually
In this particular machine
38 kHz class demodulator, three pins, sometimes already connectorized.
Where to look
Front bezel, often a separate board.
How to get it out
Keep the board.
The condition to expect
Almost always good.
Prize — take this firstDVD or Blu-ray player1 · usually
In this particular machine
Three-pin receiver.
Where to look
Front panel.
How to get it out
Keep the little board.
The condition to expect
Good.