Road-speed limiter
Page 18
If you've noticed an error in this article please click here to report it so we can fix it.
A VARIABLE road-speed limiter for commercial vehicles has been introduced by Romatic of Derwent Street trading estate, Safford.
Known as the Varispeed, it uses micro-electronics to produce a system which has a top speed specified by the operator in addition to three intermediate settings of 30, 40 and 50mph.
The intermediate speed can be selected by the driver according to the speed limits prevailing but the top speed is as specified.
The mechanical part of the speed control system is basically similar to that of the Romatic speed limiter which was introduced a year ago.
It is activated hydraulically and has its own oil reservoir operating the control cylinder. Romatic claims that it can be used on either rod or cable throttle linkages.
The road speed is monitored by means of an eight-pole magnetic sensor which gives eight signals per revolution compared with the one signal/rev of a propshaft sensor. The Romatic sensor fits between the tachograph drive and the gearbox in an adaptor unit.
As the road speed reaches the selected speed option, a solenoid opens the oil pump thus activating the control cylinder.
Romatic claims that in the case of a system malfunction, the controller will "fail safe" and the throttle will' operate as normal.
The cost of the Varispeed is £325 while a conversion kit is available to adapt existing Romatic controllers to variable control at £100.