FMR-201
27MHz FM Receiver, PCB Strip Receiver with Open Collector Output

Features

• Crystal Controlled
• Low supply voltage, highest reliability, low power drain
• Single Channel Receiver

 

 

Description
Technical Data
Block Diagram


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Description

The FMR-201 is a crystal controlled single channel receiver, comprising of receiving, decoding and open collector output sections. A specially designed LARGE SCALE INTEGRATED CIRCUIT (LSI) is employed in the decoder section, which ensures operation at low supply voltage, highest reliability, associated with very low power drain.

The receiver works on a digitally encoded 27 MHz frequency modulated (FM) signal. It may be used in an application that requires the 27MHz receiver to be mounted on a printed circuit board.

If the code of the input signal (from a transmitter) matches the setting of the coding switch on the receiver (up to 4096 combinations), an output is obtained i.e. the open collector is switched to ground.

Connection to the receiver is via a six-way female connector. The male connector can be soldered onto any type of printed circuit board, requiring a 27 MHz receiver. The male connector is available as a Nylon 6-way male low profile connector, part number 6WLP or high profile connector part number 6WHP. See design dimensions page for more details.

A proper 27 MHz CB-Antenna will give a reliable control range of up to 200 metres, when used with Elsema’s FMT-301, FMT-302, FMT-304 transmitters. If a CB-Antenna is used, the shield of the cable must be connected to the "minus terminal". .

The default mode is in momentary mode, i.e. the output transistor is only activated while the correct signal is received. When a flip/flop mode (toggling the output every correct incoming signal) is required the flip/flop link should be soldered into the receiver. In flip/flop mode, the output transistor is on at the initial "power-up".

Care must be taken, not to bring a receiver near strong magnetic fields, such as DC-Motors, speakers, magnets for reed switches, transformers etc. as it would magnetise the coils and may cause severe de-tuning.

Technical Data

Supply Voltage 7.5-20VDC, absolute max +30VDC
Current Consumption 10mA stand by
Receiving Frequency 27.145MHz (Other freq. available: 27.045, 27.195 & 27.455MHz. NB. 27.455 freq. is not available for Australia )
Type of Crystal Used 26.690MHz, 3rd overtone, 20pF, 30ppm at 0-50°C
IF Freq 455kHz
Selectivity At least -40dB at ±10kHz
Sensitivity Better than 1uV (for transistor to switch on)
Type of demodulation Narrow-bandwidth Frequency Modulation (FM)
Band Width ±2.5kHz
Decoding System Onboard 12-way coding switch (4096 digital channels)
Output

Transistor output maximum-swithcing 100mA/40VDC
Transistor is normally "off", it switches "on" if correct code is received
Joining "AL" tracks on copper side of PCB will change output from "momentary" to "alternating"

Connections 6-way female connector type
Male connector is soldered to a PCB
Antenna 50 ohms, 27MHz CB-Antenna or approximately 300mm long wire for short range applications.
Dimensions 88 x 43 x 15mm
Mounting Hole Size 3.97mm or 5/32"
Mounting Hole Spacing Length 81.28mm (3.2")
Width 35.56mm (1.4")
Weight 28.5g
Compatible Transmitters FMT-... series

NB:
All input & outputs are protected against possible transients or static charges
If antenna is a piece of wire, install away from metal parts
Keep coils L1 & L2 away from magnetic components such as speakers, motors, transformers etc
Do not change factory tuning of L1 & L2 coils

Circuit Diagram

Dimensions

 


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