Push Button (Tactile Switch)Momentary SPST-NO tactile switch
Press to connect, release to open.
A push button is a momentary switch: its contacts close only while the plunger is held down, and a spring opens them again on release. Tactile switches like the Omron B3F add a snap dome, so the press is felt as a click at a defined force. The B3F is made for logic signals, not loads: 1–50 mA at 3–24 V DC (resistive). Closed, the contact measures at most 100 mΩ at first; open, more than 100 MΩ. A microcontroller reads it through a pull-up resistor, and because the contacts bounce for up to 5 ms the program or an RC filter must ignore the first few milliseconds after each edge. This page covers the 6 × 6 mm B3F-1000 and the 12 × 12 mm B3F-4000, the two push buttons in ProTech. Each has four leads but only two contacts: the two leads joined across the body form terminal 1, the other two terminal 2. The page, ProTech and the KiCad footprints number them 1 and 2.
Key specifications
Wire one terminal to the input and the other to ground, give the input a pull-up, and the pin reads HIGH until the button is pressed. Keep the current within 50 mA: a tactile switch signals, a transistor or relay switches the load.
Contact rating50 mA at 24 V DC maximum, resistive · logic signals
Contact resistance100 mΩ maximum, initial · open > 100 MΩ
Contact bounce≤ 5 ms · debounce in software or with RC
Life1–3 M operations · 6 mm / 12 mm
Package details
B3F-1000 · 6 × 6 mm
| Property | Details |
|---|---|
| Manufacturer | Omron |
| Part number | B3F-1000 |
| Package | 6 × 6 mm |
| Connections | 2 pins |
| Mounting | Through-hole |
| Lead pitch | 6.50 × 4.50 mm pad spacing |
| Package code | push-6mm |
| Thermal reference | Contact heating at the rating: (50 mA)² × 100 mΩ = 250 µW |
Selected parts and terminals
Manufacturer scope and page conventions
Manufacturer specifications 6 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Reference parts | Omron B3F-1000 (6 × 6 mm) · B3F-4000 (12 × 12 mm) | Omron B3F Tactile Switch, Cat. No. A070-E1-08 |
| Contact form | SPST-NO, momentary | Closed only while the plunger is held |
| Leads | 4 leads, 2 contacts | The two leads across the body are joined inside |
| Terminal 1 | Pads 1 (two leads) | ProTech pin 1 · KiCad pad 1 |
| Terminal 2 | Pads 2 (two leads) | ProTech pin 2 · KiCad pad 2 |
| Proteus symbol | BUTTON | 2 pins; ProTech’s Push Button models it |
No specifications match. Try a parameter name or a unit.
If unsure which leads are joined, measure: the pair that reads 0 Ω unpressed is one terminal.
The two push buttons
From each manufacturer’s sheet · the numbers ProTech’s model and checks use
Manufacturer specifications 13 parameters
Scroll sideways to see all columns.
| Specification | Omron B3F-1000 | Omron B3F-4000 |
|---|---|---|
| Contact rating (resistive) | 1–50 mA at 3–24 V DC (resistive) | 1–50 mA at 3–24 V DC (resistive) |
| Minimum load | 10 µA at 1 V DC | 10 µA at 1 V DC |
| Contact resistance | 100 mΩ maximum (initial) | 100 mΩ maximum (initial) |
| Insulation resistance | ≥ 100 MΩ at 250 V DC | ≥ 100 MΩ at 250 V DC |
| Dielectric strength | 500 V AC for 1 min | 500 V AC for 1 min |
| Operation | 0.98 ± 0.29 N (100 gf); release ≥ 0.2 N | 1.27 ± 0.49 N (130 gf); release ≥ 0.29 N |
| Travel | pretravel 0.25 mm | pretravel 0.3 mm |
| Life | 1 000 000 operations | 3 000 000 operations |
| Contact bounce | ≤ 5 ms | ≤ 5 ms |
| Operating temperature | −25 to +70 °C | −25 to +70 °C |
| Size | 6 × 6 mm, plunger Ø3.5 mm, 4.3 mm high | 12 × 12 mm, plunger Ø7.1 mm, 4.3 mm high |
| Terminals | 6.5 × 4.5 mm (4 leads) | 12.5 × 5.0 mm (4 leads) |
| Look | black body, metal cover with four tabs, ivory round plunger | black body, metal cover, large ivory round plunger |
No specifications match. Try a parameter name or a unit.
Contact resistance is the initial maximum; it rises with wear and contamination. Ratings are for resistive loads.
How ProTech models it
The same numbers drive the simulator, its checks and this page
Manufacturer specifications 6 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Closed | 100 mΩ between pins 1 and 2 | I = V / Rc, P = I² · Rc |
| Open | No branch | Insulation resistance not modelled |
| Rating check | Warns above 50 mA or 24 V | Pop-up Check page and the status bar |
| Bounce | 5 ms in the Lab only | Not in the running circuit |
| Modes | NO (closed while pressed) · NC (open while pressed) | Properties; latching keeps its saved position |
| Size | Drawn at true size | 6 × 6 mm or 12 × 12 mm against the Uno |
No specifications match. Try a parameter name or a unit.
Change the switch in Properties: the drawing, rating, contact resistance and PCB footprint follow it.
Reading it with a microcontroller
5 V input with a pull-up resistor
Manufacturer specifications 6 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Pull-up | 10 kΩ to 5 V (or INPUT_PULLUP) | Input idles HIGH |
| Pressed current | 0.5 mA | 5 V / 10 kΩ, far below 50 mA |
| Pressed voltage at the pin | ≈ 50 µV | 0.5 mA × 100 mΩ contact resistance |
| Contact heating | 0.025 µW | (0.5 mA)² × 100 mΩ |
| RC debounce | 10 kΩ + 100 nF → τ = 1 ms | Settles within about 5 τ = 5 ms, the bounce time |
| Software debounce | Read again 10–20 ms after an edge | Longer than the 5 ms bounce |
No specifications match. Try a parameter name or a unit.
Never switch a motor or lamp through a tactile switch: let it drive a transistor or relay.
Package
B3F-1000 · 6 × 6 mm
Manufacturer specifications 5 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| 6 mm body | 6 × 6 mm, plunger Ø3.5 mm, 4.3 mm high | B3F-1000 |
| 12 mm body | 12 × 12 mm, plunger Ø7.1 mm, 4.3 mm high | B3F-4000 |
| 6 mm pads | 6.50 × 4.50 mm pad spacing, Ø1.1 mm drill | KiCad SW_PUSH_6mm |
| 12 mm pads | 12.50 × 5.00 mm pad spacing, Ø1.2 mm drill | KiCad SW_PUSH_12mm |
| Mount | Through-hole | Leads soldered; the plunger faces up |
No specifications match. Try a parameter name or a unit.
Footprints are KiCad’s, the same as ProTech’s PCB page; check the drill against your board house.
Connections by function
Select a pin for its function, connection guidance and electrical notes.
Switch contact2 pins
Switch contact2 pins
Push Button (Tactile Switch) at a glance
Follow the labeled connections and functional stages
How it works
3 stages · Explore one step at a time
Released: the dome holds the contacts apart
A small metal dome sits over the fixed contacts. Unpressed, it does not touch the centre contact, so terminals 1 and 2 are open (insulation ≥ 100 MΩ).
Pressed: the dome snaps and closes the circuit
At about 0.98 ± 0.29 N (100 gf) the dome snaps through with the click you feel, and its centre lands on the inner contact: terminal 1 meets terminal 2 through at most 100 mΩ.
The contacts bounce, then settle
Metal on metal rebounds a few times before it rests. For up to 5 ms the input may see several edges; a debounce delay or an RC filter turns them into one.
Step 1 of 3
Push Button (Tactile Switch) in a circuit
5 V, a 10 kΩ pull-up, the button to ground.
Connect it, step by step
Follow the component values and pin connections
Pull the input up
10 kΩ to 5 V (or INPUT_PULLUP) makes the pin read HIGH while the button is open.
Button to ground
Pressed, the button shorts the pin to ground: it reads LOW, and 0.5 mA flows.
Debounce
Ignore edges for 10–20 ms after the first, or add 100 nF across the button.
Inside Push Button (Tactile Switch)
Leads, fixed contacts, snap dome and plunger.
Explore the circuit
Select a stage to see its role and connections
Two terminals, four leads
Each terminal has two leads joined by a strip in the base; the four legs only hold the switch firmly.
The snap dome
Pressing flattens the dome past its tipping point: the click, and the contact.
Return
Released, the dome springs back and lifts the plunger: the contact opens again.
Selected package6 × 6 mmB3F-1000
Physical connections2 pinsPackage-specific numbering
Reference collection6 tables36 parameters & pin functions
Pin reference
Signal names, electrical functions and connection guidance
Physical pin numbers2 pins
Scroll within the table to see all columns and rows.
| Pin | Signal | Type | Function & connection |
|---|---|---|---|
| 1 | Contact terminal 1 | Pads 1: two leads on opposite sides of the body (6.5 mm apart on the 6 mm switch, 12.5 mm on the 12 mm one), joined inside.Connection guidanceConnect to the microcontroller input; with INPUT_PULLUP the input idles HIGH. A switch has no polarity: terminals 1 and 2 may be swapped. | |
| 2 | Contact terminal 2 | Pads 2: the other two leads, also joined inside. Pressing the plunger connects terminal 1 to terminal 2.Connection guidanceConnect to ground for an active-low button (pressed reads LOW). Closed: at most 100 mΩ between the terminals (initial). Leads 1 and 2 on the same side are the switched pair. |
No pins match these filters. Try another signal name or reset the filters.
Selected parts and terminals
Manufacturer scope and page conventions
Manufacturer-referenced values6 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Reference parts | Omron B3F-1000 (6 × 6 mm) · B3F-4000 (12 × 12 mm) | Omron B3F Tactile Switch, Cat. No. A070-E1-08 |
| Contact form | SPST-NO, momentary | Closed only while the plunger is held |
| Leads | 4 leads, 2 contacts | The two leads across the body are joined inside |
| Terminal 1 | Pads 1 (two leads) | ProTech pin 1 · KiCad pad 1 |
| Terminal 2 | Pads 2 (two leads) | ProTech pin 2 · KiCad pad 2 |
| Proteus symbol | BUTTON | 2 pins; ProTech’s Push Button models it |
No specifications match. Try a parameter name or a unit.
If unsure which leads are joined, measure: the pair that reads 0 Ω unpressed is one terminal.
The two push buttons
From each manufacturer’s sheet · the numbers ProTech’s model and checks use
Manufacturer-referenced values13 parameters
Scroll within the table to see all columns and rows.
| Specification | Omron B3F-1000 | Omron B3F-4000 |
|---|---|---|
| Contact rating (resistive) | 1–50 mA at 3–24 V DC (resistive) | 1–50 mA at 3–24 V DC (resistive) |
| Minimum load | 10 µA at 1 V DC | 10 µA at 1 V DC |
| Contact resistance | 100 mΩ maximum (initial) | 100 mΩ maximum (initial) |
| Insulation resistance | ≥ 100 MΩ at 250 V DC | ≥ 100 MΩ at 250 V DC |
| Dielectric strength | 500 V AC for 1 min | 500 V AC for 1 min |
| Operation | 0.98 ± 0.29 N (100 gf); release ≥ 0.2 N | 1.27 ± 0.49 N (130 gf); release ≥ 0.29 N |
| Travel | pretravel 0.25 mm | pretravel 0.3 mm |
| Life | 1 000 000 operations | 3 000 000 operations |
| Contact bounce | ≤ 5 ms | ≤ 5 ms |
| Operating temperature | −25 to +70 °C | −25 to +70 °C |
| Size | 6 × 6 mm, plunger Ø3.5 mm, 4.3 mm high | 12 × 12 mm, plunger Ø7.1 mm, 4.3 mm high |
| Terminals | 6.5 × 4.5 mm (4 leads) | 12.5 × 5.0 mm (4 leads) |
| Look | black body, metal cover with four tabs, ivory round plunger | black body, metal cover, large ivory round plunger |
No specifications match. Try a parameter name or a unit.
Contact resistance is the initial maximum; it rises with wear and contamination. Ratings are for resistive loads.
How ProTech models it
The same numbers drive the simulator, its checks and this page
Manufacturer-referenced values6 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Closed | 100 mΩ between pins 1 and 2 | I = V / Rc, P = I² · Rc |
| Open | No branch | Insulation resistance not modelled |
| Rating check | Warns above 50 mA or 24 V | Pop-up Check page and the status bar |
| Bounce | 5 ms in the Lab only | Not in the running circuit |
| Modes | NO (closed while pressed) · NC (open while pressed) | Properties; latching keeps its saved position |
| Size | Drawn at true size | 6 × 6 mm or 12 × 12 mm against the Uno |
No specifications match. Try a parameter name or a unit.
Change the switch in Properties: the drawing, rating, contact resistance and PCB footprint follow it.
Reading it with a microcontroller
5 V input with a pull-up resistor
Manufacturer-referenced values6 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Pull-up | 10 kΩ to 5 V (or INPUT_PULLUP) | Input idles HIGH |
| Pressed current | 0.5 mA | 5 V / 10 kΩ, far below 50 mA |
| Pressed voltage at the pin | ≈ 50 µV | 0.5 mA × 100 mΩ contact resistance |
| Contact heating | 0.025 µW | (0.5 mA)² × 100 mΩ |
| RC debounce | 10 kΩ + 100 nF → τ = 1 ms | Settles within about 5 τ = 5 ms, the bounce time |
| Software debounce | Read again 10–20 ms after an edge | Longer than the 5 ms bounce |
No specifications match. Try a parameter name or a unit.
Never switch a motor or lamp through a tactile switch: let it drive a transistor or relay.
Package
B3F-1000 · 6 × 6 mm
Manufacturer-referenced values5 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| 6 mm body | 6 × 6 mm, plunger Ø3.5 mm, 4.3 mm high | B3F-1000 |
| 12 mm body | 12 × 12 mm, plunger Ø7.1 mm, 4.3 mm high | B3F-4000 |
| 6 mm pads | 6.50 × 4.50 mm pad spacing, Ø1.1 mm drill | KiCad SW_PUSH_6mm |
| 12 mm pads | 12.50 × 5.00 mm pad spacing, Ø1.2 mm drill | KiCad SW_PUSH_12mm |
| Mount | Through-hole | Leads soldered; the plunger faces up |
No specifications match. Try a parameter name or a unit.
Footprints are KiCad’s, the same as ProTech’s PCB page; check the drill against your board house.
No matching rowsTry a pin name, parameter, unit or test condition, or reset the filters.
Microcontroller inputs
Start, reset, menu and mode buttons read through a pull-up; the classic first input of every Arduino project.
Manufacturer application guideReset and boot buttons
Most boards pull RESET up and use a tactile switch to ground it.
Manufacturer application guideKeypads and panels
Rows and columns of tactile switches scanned by a microcontroller; the 12 mm size takes a keycap or a cap with a larger touch area.
Manufacturer application guideTake it into ProTech
Find Push Button (Tactile Switch) in the Components Library to place its schematic symbol and connect its pins.
Working switch example available in ProTechOpen ProTech