Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Turn Signal Module - Lets build a better one!

Looking good, Cad drawings done and into a small production run we go, watch this space for updates from the trials...

Blank PCBs have arrived!

Have the real life trials started and if yes how is it performing?

Since this theory could apply to virtually every vehicle on the road, I'm somewhat sceptical the magnitude and duration of such back emf could do damage, irrespective of battery state. An easy way to check though would be a reverse biased LED indicator since most have polarity protection. Such can certainly display the back emf from a small (non diode) 12 volt relay coil with a brief flash, and over a 60 foot cable run as I found out when snagging a warning light issue on remotely operated lamp on my narrowboat.

This specific problem only relates to vehicles that have CMOS logic gate inputs connected directly to '12V' power electronics.

I started debugging my software on the TSM2 board at 8am this morning. There are/were a few bugs to squish. It is progressing well and relays are switching on and off but once the Hazards button has been pressed all indicators flash even when the button is subsequently released! My Audi A3 had the same 'feature' but that was caused by the previous owner spilling a drink over the hazards button thus making the mechanism rather sticky!

I expect to post the first prototype to a willing guinea-pig this weekend.

Good news Alister. Assuming the guinea pig trial goes well, when do you expect to be taking orders and supplying the TSM2? Are you still going for a different colour box to differentiate the new TSM?

Hi Alister
Will any of the functions in your unit be programmable?
I am thinking of the car speed before the flasher times out - I would not want it to time out for example so could possible set to 0 , so the indicators stay on until manually cancelled ?
Please ignore if already a function !
Thanks - a prospective customer !

The plan is to stick to black. We can easily put a label on to show it is a TSM2 / AMB.

I am waiting for 'Mr. Big', the financial backer, to sort out the box suppliers. The box manufacturers have recently been sent a circuit board with connector and relays on it so that they can ensure my tech drawing of the required cut-out slot is perfectly aligned because there is a margin of about half a millimetre. Once the boxes are here we can easily start a production run as I can usually get a surface-mount circuit board run achieved in-house, over a weekend.

I spent most of yesterday sorting out software bugs, and am very pleased with progress.
The last thing done was to calculate speed from the VSS signal. As I don't know the sensor type or the gear ratio between sensor and wheel, I can only ensure that the TSM2 follows the old TSM.

One final job to do is add the auto-cancel 'feature', now I have an idea of vehicle speed.
I intend to make it programmable such that there are 3 possible modes: 7 seconds, 14 seconds and Off.

Tentative procedure to change the current mode:
Ignition ON
Wait two to five seconds.
Press the Hazards button.
After a flash, indicate right or left briefly. Left makes the time go up from 7 to 14 seconds to off ( infinite time!), right makes the time go down in sequence: off->14->7.
release the Hazards button within ten seconds of ignition ON.

After ten seconds the hazards warning lamp will/should flash 12 brief pulses, then a gap of 2 seconds, then 12 more pulses. These pulses indicate minimum and maximum battery voltage. If instead of indicating left or right during the above procedure, you start the engine, the number of pulses will change as the minimum voltage shows crank voltage and the maximum is either the alternator charge voltage or undesirable spikes as mentioned earlier. This has only been tested on a bench power supply so my guinea-pig will have to report back what really happens.


Normally one would simply switch ignition on, start the engine, and drive away. No flashing lights will be seen; the TSM2 should behave normally.

Glad you put the last paragraph in as I was getting worried with all the potential flashing light indications 😁. I think 14 seconds indicator duration will do me fine, it is just the auto cancel as you coast up to a junction that causes problems with the standard TSM.

Sounds cool. I want one!