DTMF REMOTE RELAY CONTROL

The dtmf relay control unit is intended for any application which may require remote dtmf relay on/off switching by a radio link. Primarily aimed at the radio amateur (ham) user,  these types of products have been well proven in applications for remote switching of audio signals, ptt isolation,  or general remote control of equipment in a wide range of scenarios. 

The units features.

• Compact size  ABS case 140mm wide x 110mm deep x 35mm high

• Uncased  version for insertion into end user enclosure

• Eight relay contact outputs (see scenarios)

• Two versions available (asm file can be made available)

• Wide range of dc switching currents from 10uA to 2Amps

• Relays carry UL, CSA, and conform to FCC Part 68 standards

• LED monitoring of each output

• 12 / 13.8 Volt DC socket

• Diode polarity protected

• Outputs via 4 way molex style headers

There are two versions available both based upon the same pcb which is 118mm by 97mm. Each relay output has an led monitoring it's status located along the front edge of the pcb. All dc power, and relay contacts are available along the rear edge of the pcb.  Both units utilise a DTMF receiver, a PIC controller, together with a relay driver, and high quality Omron relays. The pic asm code is available to purchasers should they wish to customise their unit. The unit requires a 12 or 13.8V dc supply which is polarity protected on the board by a series diode. Each unit is supplied with a user manual giving schematic details together with operating notes.  Customised versions are can be made available by quotation to the email address to EZE(UK).

 The first version has eight independent change over relays, which are turned on, or off by a sequence of dtmf commands.  See Scenario 1 Or by using the link matrix on the pcb the first four relays can be slaved from one. ie. Relay one dtmf string can also energise relays 2, 3, and 4. Or only relay 2, or relays 2 and 3. Making the unit more versatile in it's applications.  For example you may use relay 1 to switch received audio paths in a link, and want to switch tx audio paths, or ptt's at the same time, so slaving or ganging the relays to one command string can be very useful.

The second also has eight relays, four of which are configured to form a single pole 4 way switch.  Three are configured as independent change over relays, and the eighth is configured as a four second switch which responds to the first tone in any sequence and is used to mute the audio line to a repeater or radio link whilst the dtmf tones are being sent. This version being more suitable to rf repeater or link use. See Scenario 2  

Note that these units are intended to switch dc or low level signal voltages upto 48V. If it is intended to use them to switch AC voltage supplies higher than 48V an external relay would be required with sufficient isolation between the switch feed, and the supply it is switching.

Typical image picture. Further information including customised versions can be obtained by contacting us by email to the address below.

Payment by Paypal , or cheque in pound sterling. If paying by cheque please email for details .

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