Towing or Caravan Relays can be separated into four main product types according to their function.
Monitors are devices that sense the flow of current to the trailer or caravan flashers,
and fulfil a legal requirement to warn of a bulb failure on the trailer flashers.
|The simplest device is the audible monitor TEM1A
which is boot fitting, and which interrupts the individual flasher circuits at the point at which the
12N cable attaches to the car’s flasher circuits.
Feedback to the driver is via an internal 2khz electromagnetic buzzer, which is sweeter sounding than the
old style 500hz buzzer that it replaces, is at a pitch that is more responsive to the ear, and is much more
Yet the sound is much less annoying than the high pitched square wave piezo enunciated types.
The use of surface mount technology and a mini-buzzer probably makes this the smallest monitor on the market.
A version is available fitted with a twin 5m flying lead (TEM1B)
which carries a signal back to the console to operate either a remote buzzer or a signal lamp. (Tell Tail)
A so called Flasher Booster version is also available (TEB2MA)
, which is really categorised as a bypass
relay (see below), and is for use where the car’s own flasher circuits cannot support the extra demand
of the trailer’s flashers. This device has the unique ability to double as both an audible boot located monitor
and also as a remote indicating monitor, thus reducing stocking requirements.
A front fitting monitor is also available (TEM2A)
which interrupts the supply to or from the Flasher Relay.
The device is electronically tuneable in order to cancel out the contribution from the car’s own flashers.
Note that this monitor should not be compared with the very unreliable front fitting reed switch devices.
Fog Cut-Off Relays