Why use lamp simulation for flasher/indicator lights?
Most flasher/indicator relays will measure the load applied and will by means of the control lamp in cab, indicate if the correct number of lamps are connected as well as the if the lamps are of the correct wattage.
Flasher/indicator relays are normally defined, for example as a 3+1 relay, which means 3x21W lamps on the truck and 1x21W lamp on the trailer. In the cab there are two control lamps, a C1 lamp for the truck and a C2 lamp for the trailer. If an 18W lamp is fitted in place of a 21W lamp the control lamp C2 will switch off and in this way indicate a fault condition.
If one wants a flasher/indicator relay to indicate correctly when a 24W vehicle is towing a 12V trailer, lamp simulation is necessary because the current consumption of a 12V / 21W lamp is 1,85Amp. illustrated in current graph Fig.2. and current consumption of a 24V / 21W lamp is 1,0 Amp. illustrated in current graph Fig.1.
TLUB is designed to simulate the current waveform of a 24V lamp very accurately.
TLUC is a simplified simulation utilising a combination of resistor and pulse technique. This technique will make most flasher/indicator relays indicate fairly accurately.
When using a series resistor or a linear voltage converter that will reduce the 24 volt to 12 volt the disadvantage is that the relay’s control function will interpret a 12V / 21W lamp as 38W lamp and in most instances the C2 control lamp will indicate incorrectly.
- Input voltage: 24 V (20 - 32 V)
- Output voltage: 14V RMS 130 Hz. (with 28V input)
- Efficiency: Flasher output 90% Other outputs 95%
- Dimensions: L.105 MM x B.110 MM x H.43 MM
- waterproof units in aluminium housing.
- Cable connections: 24V input: 1 meter x (7x1.0 mm2 + 1x2,5 mm2)
- 12V output: 1 meter x (7x1.0mm2 + 1x2,5 mm2)
Output ratings:
- Flasher outputs: 2x21W
- Tail light: 2x30W
- Fog light rear: 2x21W
- Reverse light: 2x21W
- Stop light: 2x21W