Dorman TF/K

Flasher unit acquired in May 2020.

This flasher unit was removed from a redundant post on High Street, Eckington, and I was pleased to be able to acquire it, as this type was the first that I remember seeing - one was installed on the route that led to my nursery, and would be operating during the journey. Inevitably, on occasion, one of the two lamps would have failed, leading to the one remaining lamp being left to flash on its own, which I loved to witness!

A screenshot taken from Google Street View of the flasher unit, as it appeared in May 2019.

The flasher unit features a plastic casing, with two security bolts positioned between the two lenses used for securing the front cover under normal operation. These have rusted on this example, but on the example that I recall, they were clean and shiny - in all likelihood, the fitting would have been relatively new at the time. The two lenses are very similar in design (albeit, slightly smaller) to those employed on the Conelite, another Dorman product.

Releasing the bolts allows the front cover to pull forwards, and hinge open to the right, in order to gain access to the lamps and internal wiring. The optic areas surrounding the lamps are painted white, in order to maximise reflectance. The two lamps fitted here carry handwritten installation dates of June 2010. Also visible here is the key switch used to switch the unit on and off manually as required. Behind both lamps are v-shaped metal struts with threaded rods passing out of the back of the fitting. To these, two more v-shaped struts attach, which are secured by tightening bolts against them - this method ensuring that the fitting is clamped tightly to its post.

The hinge is designed to make the front cover fold back out of the way, ensuring that it doesn't hinder the removal of the controller in the event that this requires replacing.

A (slightly mouldy) label is positioned above the upper lamp; this contains the text:

Twin FLASH Types TF/M and TF/K

The unit is designed for operation on 240 V AC mains supply.

60 Watt bulbs must be fitted.

To operate:

a) Type TF/M - Depress the push button switch, which is accessible through the small hole in the base of the housing, with the special T key provided.

b) Type TF/K - Introduce the Yale-type key into the key locking switch located in the base of the housing, and turn.

Dorman Traffic Products Ltd: Southport PR9 8LA England. Tel 0704 20911.

A wiring diagram is provided on the front of the controller unit.

A very faint handwritten comment on the side of the label tells us that the unit was tested on the 23rd September 1989.

The controller is intended to be removed by loosening the two threaded plastic covers over the bayonet lampholders, and then pulling it away from the central support frame. Unfortunately, with the frame having rusted over time, the covers were jammed and had to be broken away.

Some time before this unit was acquired, a spare controller entered the Collection - this carried the stock code ST840. The two wires visible would connect with fixed wires within the fitting (see above), allowing swift replacement of the controller in the event of failure. This unit was tested on the 4th April 1990; the handwriting is very similar, suggesting that both controllers were tested by the same person.

Although the controller casing can be opened, it isn't intended to be repairable - wax has been poured onto the circuit board during manufacture, sealing it against ingress. Only the tops of taller components are visible in the solidified compound.

Forest City TAF |




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