Switches and relays

Switches open or close a connection. Some work only while pressed (momentary); others retain their position (latching). A relay uses an inductor coil; a reed switch uses a magnet.

6 types2 groupsSymbol IEC

Manual control

6 × 6 mm tactile button

ButtonInput that closes the circuit while held: reset, user input

Size: 6 × 6 mm
Type: NO (normally open)
Value: 50 mA, 12 V DC

SS12D00 (1 pole, 2 throws)

Slide switchSwitching small circuits on and off or choosing between two paths

Type: SPDT
Position: 2
Operation: Latching

MTS-102 (SPDT, 2 positions)

Toggle switchClear on-off from the panel; the device’s main switch

Type: SPDT · SPST
Current: A few A
Mounting: Panel (6 mm hole)

8-position DIP switch

DIP switchA few bits of settings on the board: address, mode, option

Position: 4 · 8
Range: 2.54 mm
Current: Signal level

By electricity or a magnet

SRD-05VDC-SL-C

RelaySwitching a separate, more powerful circuit with a microcontroller

Inductor: 5 V, ≈70 Ω
Inductor current: ≈71 mA
Contact: 10 A

Reed switchContactless on-off switching with a magnet: door, window, counter

Type: NO (normally open)
Trigger: Magnet
Current: Low

Which one should I choose?

For operation while pressed, stopping on release

Button

Momentary operation, fits straight into a breadboard.

If you will leave a small circuit on or off

Slide switch

Keeps its position and is small.

If you want a main switch clearly visible on the panel

Toggle switch

Secured to the panel with a nut so it stays in place.

If you will choose the board’s setting with a few bits

DIP switch

Many small switches side by side in one body.

If you will switch a separate, powerful circuit with a microcontroller

Relay

The control circuit and load circuit are electrically separate.

If you will detect without contact when the door opens

Reed switch

Closes with a magnet, no parts rub against each other.

Compare6 types · 5 features

Type	Operation	What triggers it	Contact	Current	Typical use
Button	Momentary	Finger	SPST, NO	≈50 mA	Input, reset
Slide switch	Latching	Finger	SPDT	Low	On-off, selection
Toggle switch	Latching	Finger	SPST · SPDT	A few A	Main switch
DIP switch	Latching	Pen tip	SPST × 2–12	Signal (≈25 mA)	Address, mode selection
Relay	Connected to inductor coil	Inductor current	SPDT (NO + NC)	10 A (contact)	Switching a heavy load
Reed switch	Attached to a magnet	Magnet	SPST, NO	Low	Door sensor

Contact currents vary by model; check the limit in the datasheet.