> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt

# Magnetic contact switch (door sensor)

**Type:** Product page · **SKU:** ADA375 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia)
**Page:** https://core-electronics.com.au/magnetic-contact-switch-door-sensor.html ([markdown](https://core-electronics.com.au/magnetic-contact-switch-door-sensor.html.md))

## Retired product

This product is retired and no longer available for purchase. Replaced by: CE09248.

**Replacement:** https://core-electronics.com.au/catalog/product/view/sku/CE09248

## How to buy

- **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works)
- **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt
## Description

This sensor is essentially a reed switch, encased in an ABS plastic shell. Normally the reed is 'open' (no connection between the two wires). The other half is a magnet. When the magnet is less than 13mm (0.5") away, the reed switch closes. They're often used to detect when a door or drawer is open, which is why they have mounting tabs and screws. You can also pick up some double-sided foam tape from a hardware store to mount these, that works well without needing screws.

### Technical Details

- Normally open reed switch
- ABS enclosure
- Rated current: 100 mA max
- Rated voltage: 200 VDC max
- Distance: 15mm max
 
Dimensions:

- Box size (each side): 29mm x 14mm x 9mm / 1.1" x 0.6" x 0.4"
- Cable Length: 305mm ± 12mm / 12" ± 0.5"
- Weight (per side): 5.4g
 
Netduino driver and Netduino sample. This sample shows how to use an interrupt handler to respond to a button press or a magnetic contact switch closing.

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/3/7/375-00.jpg)