silverfox4 Posted January 26, 2019 Report Share Posted January 26, 2019 Any suggestions for locating an OD-engaged indication light and a fan over-ride switch. I have the following style devices )there may be better) One option is to re-purpose the ash tray but not sure if that is a good idea, or exactly how to go about doing that. Another is to fabricate a new bracket to fit next to the H -support, but that could interfere with the old knees.. I assume many members have undertaken similar exercises - all suggestions welcome Cheers Quote Link to post Share on other sites
RogerH Posted January 26, 2019 Report Share Posted January 26, 2019 There are not too many places to put extra switches or LED's I put a plate across the radio aperture and popped some switches there. As for the OD light I put that in the switch cowling on the steering column. Roger Quote Link to post Share on other sites
TorontoTim Posted January 27, 2019 Report Share Posted January 27, 2019 Cunning, Roger!! Quote Link to post Share on other sites
RogerH Posted January 27, 2019 Report Share Posted January 27, 2019 47 minutes ago, TorontoTim said: Cunning, Roger!! The thing is you do not want to be looking around the dash board for warning lights. You need to be looking ahead. Roger Quote Link to post Share on other sites
barkerwilliams Posted January 27, 2019 Report Share Posted January 27, 2019 A sharp metal edge above a leg would not be my choice. At least bend a deeper front backwards to create a lower surface against the leg, then double the rearmost edge over against itself to form a smooth rear edge, to eliminate a cutting edge. Alan Quote Link to post Share on other sites
silverfox4 Posted January 27, 2019 Author Report Share Posted January 27, 2019 Very clever option for the light Roger, brilliant idea! I will check for clearances inside the cowl to see if the LED I have will be OK, Did you connect to the relay or ....? Alan, yes that is the plan for the switch including vinyl wrap, but only going this far until other idea surface or the grey matter wakes up (also pondered option of a switch on the headlight stalk) Cheers, Alf Quote Link to post Share on other sites
RogerH Posted January 27, 2019 Report Share Posted January 27, 2019 Hi Alf, there is room in the cowl for the LED + socket and dropper resistor. One LED leg goes to earth the other leg then goes to the resistor and then to C2 on the OD relay. I also added a dimmer to the LED so when the lights come on (it's dark outside) the LED dims to about half power (little relay and resistor_ When driving one can see the LED if you look down at the horn button - but there is also a slight glow on the underside of the steering wheel rim (12-o-clock position) when looking straight ahead. I use a blue LED. Roger Quote Link to post Share on other sites
Malbaby Posted January 27, 2019 Report Share Posted January 27, 2019 IMHO...a toggle switch is more classic looking. Quote Link to post Share on other sites
silverfox4 Posted January 27, 2019 Author Report Share Posted January 27, 2019 Roger, you set-up is quite fancy. Isn't the dropper resistor intended to reduce the LED intensity? but you then add a further resistor for additional reduction at night? Mallaby, I agree on the toggle aspect. This version just provides for the included light indication. I'm still playing with switch options and location. Cheers, Alf Quote Link to post Share on other sites
RogerH Posted January 27, 2019 Report Share Posted January 27, 2019 5 minutes ago, silverfox4 said: Roger, you set-up is quite fancy. Isn't the dropper resistor intended to reduce the LED intensity? but you then add a further resistor for additional reduction at night? Alf Hi Alf, most LED's run off apprx 2V, so one resisitor is required to drop 10V whilst allowing apprx 0.020milliamps to flow. This will give a bright day light glow. For night time running the LED needs dimming. So with the use of a small relay another resistor is switched into series with the first So for example you have 2700 ohms for day light operation and 6800 ohms for night time. I can show a simple circuit if you wish Roger Quote Link to post Share on other sites
stuart Posted January 27, 2019 Report Share Posted January 27, 2019 I have a small light to the right of the column on the dash on my 4a (where the rheostat is on a 4) its light controlled so dims when the headlamps are on, by sheer coincidence the position is such that by refraction it also shows up in the door mirror too so always on view. Stuart. Quote Link to post Share on other sites
Lebro Posted January 27, 2019 Report Share Posted January 27, 2019 28 minutes ago, RogerH said: Hi Alf, most LED's run off apprx 2V, so one resisitor is required to drop 10V whilst allowing apprx 0.020 milli amps ! to flow. Roger Quote Link to post Share on other sites
silverfox4 Posted January 28, 2019 Author Report Share Posted January 28, 2019 Thanks Guys, I really have to get my head around the use of LED's (I aleady had the problems with the dash lights). A diagram would be appreciated thanks Roger. Stuart, did you have to drill a new opening in the 4A dash to do the light? I assume the 4's dash rheostat location is different from the 4A then. Cheers, Alf Quote Link to post Share on other sites
RogerH Posted January 28, 2019 Report Share Posted January 28, 2019 Hi Alf, PM sent Roger Dimmer circuit.docx Quote Link to post Share on other sites
stuart Posted January 28, 2019 Report Share Posted January 28, 2019 (edited) 8 hours ago, silverfox4 said: Thanks Guys, I really have to get my head around the use of LED's (I aleady had the problems with the dash lights). A diagram would be appreciated thanks Roger. Stuart, did you have to drill a new opening in the 4A dash to do the light? I assume the 4's dash rheostat location is different from the 4A then. Cheers, Alf I drilled through the wood dash but the steel backing dash already has the hole left over from the TR4 Stuart. Edited January 28, 2019 by stuart Quote Link to post Share on other sites
Lebro Posted January 28, 2019 Report Share Posted January 28, 2019 (edited) 12 hours ago, RogerH said: Hi Alf, PM sent Roger Dimmer circuit.docx Or: Bob Edited January 28, 2019 by Lebro Quote Link to post Share on other sites
ChrisR-4A Posted January 28, 2019 Report Share Posted January 28, 2019 I use a period chrome finish switch plinth on the drivers side, to centre which contains, Fan override switch, Fan warning light and Wiper sprung toggle switch for single wipe. Roger, as always your capacity to invent never ceases to impress. Chris Quote Link to post Share on other sites
silverfox4 Posted January 28, 2019 Author Report Share Posted January 28, 2019 Thanks all, extremely useful input - I now have more definitive options to work with - must be some small relay that Roger. Will check the "bits" boxes for more appropriate lights and switches and dash out to check for holes in the steel dash. Much appreciated as always, Cheers Alf Quote Link to post Share on other sites
ianc Posted January 28, 2019 Report Share Posted January 28, 2019 As, in common with many drivers of moderns, I am inclined to drive on dipped headlights in the daytime, I find that a reduced intensity "overdrive on" light becomes near invisible in sunlight. I have not yet devised a system to energise this lamp under 3 possible conditions: - night driving (headlights in use, of course!) - daytime driving with dipped headlights - daytime driving without headlights. I have a spare 3-position switch, but finding a space within arm's reach on 4VC is very difficult as the mechanics at the Works used all the usual gaps and, many years ago, I added: Kenlowe switch/indicator, cigar lighter socket, hazard indicator and the "overdrive on" indicator. Ian Cornish Quote Link to post Share on other sites
RogerH Posted January 28, 2019 Report Share Posted January 28, 2019 (edited) 30 minutes ago, silverfox4 said: - must be some small relay that Roger. Cheers Alf Hi Alf, the relay is not under the cowl on the steering column. It sits in the spaghetti behind the dash so can be any size. Hi Ian, I also drive with dipped headlights during the day. My LED points upwards and the main element of light that I see is from the underside of the steering wheel at 12-o-clock position So the move to nigt time driving does not prove a major problem For your situation you need a photoresistor/trasistor etc sensing the ambient light level rather than the cars lights. Roger Edited January 28, 2019 by RogerH Quote Link to post Share on other sites
MilesA Posted January 29, 2019 Report Share Posted January 29, 2019 One for Roger and Bob given my ignorance of electrickery and because a similar project is on the list for my 3A. If LEDs are 'plug and play' on all external lights (I presently have Bob's excellent rear LEDs and commercial cunning white / orange ones in my sidelights) and panel lights, why all this talk of 'resistors'? And ignoring the dimmer option, what would I actually ask for from whatever serves as the replacement for Maplin? Thanks as ever. Quote Link to post Share on other sites
RogerH Posted January 29, 2019 Report Share Posted January 29, 2019 Hi Miles, to make the simple LED work you need to supply it with apprx 2V. This will make it work and it will draw its own current. If you put more Volts in say 4 volts then it wil try to take more current and go 'pop' So you put a resistor in series to drop the excess volts and the LED becomes happy. You can increase the resistance and this will reduce the current and so the LED gets dimmer. On the purpose built lamps that use LED's there may be a built in series resistor or on the better stuff a voltage regulator or similar. These will run off a higher voltage r range pf voltage. So if you were going to install an LED to indicate your OD position then you have two options - Get an LED and a resistor. For a 12V system you need to drop 10V. Using Freds law of approximation V=Ir. 10 = 0,020A x R = 500. I would start with a 1000 Ohm resistor and work around that. If you get a Hi-Brightness LED the 1000R will be be bright Or you could get a 12V LED and see what happens. Roger Quote Link to post Share on other sites
MilesA Posted January 29, 2019 Report Share Posted January 29, 2019 Brilliant as ever Roger - many thanks, yet again. Quote Link to post Share on other sites
Lebro Posted January 29, 2019 Report Share Posted January 29, 2019 (edited) Well - almost correct Not all LED's drop 2V, for example the red LEDs I use in my rear lamp bulbs drop 2.4V, & white LEDs of the same type drop nearer 3V. The LED data sheet will state the typical voltage drop at various currents. What is required is to set a suitable current for the LED in question. As Roger says start with a fairly high resistance, & if possible measure the current, gradually drop the resistance to get the brightness you want, but never exceed the max continuose current rating of the LED in question. For a small LED like in Rogers example 2.2V would be fairly a typical drop for a red LED. Bob. A selection here. the last one will not need a resistor other than for dimming it down. https://www.ebay.co.uk/itm/5mm-LED-green-blue-white-yellow-red-Diffused-High-Brightness-Diode-10-100-pcs-UK/352202353622?hash=item5200e56bd6:m:mdsi3NEVW5-fc3bxNdW2DMg:rk:30:pf:0&var=621692429875 https://www.ebay.co.uk/itm/Standard-5mm-LED-Red-Diode-1-100-pcs-UK/264112329407?hash=item3d7e5252bf:m:mMfvSZ23XqbN19iAOXToQyw:rk:5:pf:0&var=563670600527 https://www.ebay.co.uk/itm/DC12V-5mm-LED-Bulb-Pre-wired-Light-Emitting-Diodes-Small-20cm-Wire-for-Hobbyists/122137301280?hash=item1c6ff35120:g:KBgAAOSwyjBW7CNp:rk:12:pf:0&var=422091872863 Edited January 29, 2019 by Lebro Quote Link to post Share on other sites
Hamish Posted January 29, 2019 Report Share Posted January 29, 2019 All this electrickery be for wizards and witches not mere mortal man. Quote Link to post Share on other sites
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