Standex Electronics introduces the SR4J series of ultra
small surface mount magnetic reed switches for non-contact position sensing in
pill cams and other medical devices. Over molded around a proven GR150 magnetic
reed switch, this J leaded version measures just 4.7 mm in length and 1.7 mm in
height. The external leads of the reed switch form a tear drop terminal pad
arrangement which preserves a greater portion of the initial magnetic circuit,
thus enhancing the magnetic sensitivity of the sensor. The SR4J series boasts a
maximum sensitivity range of 3/5 Ampere Turns (AT) (initial), and is available
in a production range from 3 to 20 AT.
In addition to a small footprint and tight sensitivity
range, the SR4J series is responsive, with a typical operating time of 0.2
milliseconds, and release time of 0.1 milliseconds (typical). The switches have
a power rating of 1 VA maximum. A switching current (Max) of 0.05 Amp, DC is
standard, as is a carry current rating (max) of 0.5 Amp, DC. Boasting an
operating range of -40 to 125°C, the SR4J is well suited for use wherever small
size and sensitivity are required for non-contact position sensing applications.