|
||
|
30th January 2009, 18:46 | #11 |
I really should get out more.......
MG ZT CDTI Join Date: Sep 2007
Location: 17500 REAUX, CHARENTE-MARITIME
Posts: 2,749
Thanks: 2
Thanked 133 Times in 90 Posts
|
Nick As the operating voltage of most LED’s is between 1.6 and 4.5V (depending on colour), you would need a small circuit of some description to provide the correct voltage from your 12V supply.
You can buy LEDs with built-in dropper resistors but then the light intensity is set. If I’m telling you something you already know ignore the following! You can calculate the dropper resistor value (R) required by using the formula: R = (VS - VL) / I, where VS is the supply voltage, VL is the LED voltage, and I is the maximum LED current. Use the nearest standard value resistor to the calculated result, but never drop below the calculated value, otherwise the LED will burn out quickly. Being a diode you shouldn’t have any problems with it in circuit with the relay output to the FBH. HTH Mick |
30th January 2009, 19:49 | #12 | |
Gets stuck in
2002 Range Rover P38 Join Date: Dec 2008
Location: Wigan
Posts: 593
Thanks: 0
Thanked 0 Times in 0 Posts
|
Quote:
Anyway, yes, you're right, a LED will be fine. And being lazy, I could probably just get one of those flashing pretend alarm-type 12v ones for a quid! tnx Nick |
|
30th January 2009, 20:46 | #13 |
I really should get out more.......
260 SE vin 214 ( last mark 1 260 ) Join Date: Dec 2006
Location: Lancashire
Posts: 2,009
Thanks: 1
Thanked 8 Times in 4 Posts
|
why not use the relay to switch another douple pole relay so you have a pole for the fb and a pole for the led circuit. seems a bit overkill though- by the time youve bought relaay led and resitor and fannied about you may as well get the timer .
__________________
[SIGPIC][/SIGPIC] |
31st January 2009, 14:52 | #14 |
Avid contributor
Rover 75 Classic SE 1.8T Join Date: Dec 2008
Location: wink
Posts: 135
Thanks: 0
Thanked 20 Times in 15 Posts
|
get a timer
Is easy to leave fbh on by mistake.
Timer is sure fire way to ensure it always goes off when you leave the car. Going to fit a red led to dash next to temp dials to indicate fbh overide on. |
31st January 2009, 18:17 | #15 |
Gets stuck in
2002 Range Rover P38 Join Date: Dec 2008
Location: Wigan
Posts: 593
Thanks: 0
Thanked 0 Times in 0 Posts
|
Got a timer kit and built it. Out of the box it does 0-15 mins (actually 0-9 mins as tested). I've increased the value of a capacitor and now got between 0-40 mins.
So, before I varnish it all and put it in the car, what is a "typical" time one would run a parking heater for? 15mins? 20mins? 30mins? Many thanks Nick |
31st January 2009, 18:20 | #16 | |
Moderator
MG-ZTT Join Date: Mar 2007
Location: Ware, Herts
Posts: 19,798
Thanks: 161
Thanked 1,249 Times in 1,036 Posts
|
Quote:
__________________
David Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics] |
|
31st January 2009, 19:25 | #17 |
This is my second home
No longer in the MGR club Join Date: Nov 2006
Location: Tipperary
Posts: 3,933
Thanks: 35
Thanked 51 Times in 35 Posts
|
I find 15 minutes usually clears my windows and makes the interior nice and toasty.
__________________
'Tis better to be silent and be thought a fool, than to speak and remove all doubt. |
31st January 2009, 21:54 | #18 |
I really should get out more.......
260 SE vin 214 ( last mark 1 260 ) Join Date: Dec 2006
Location: Lancashire
Posts: 2,009
Thanks: 1
Thanked 8 Times in 4 Posts
|
30 minutes will cover you for the coldest of days- once up to temp the fbh goes into tickover mode anyway.
noticed you are a radio ham and just up the road from me- Im licensed (G4 WCS- or Bogs !!) mainly active on 6m, so used to talking to myself !!
__________________
[SIGPIC][/SIGPIC] |
31st January 2009, 22:19 | #19 | |
Gets stuck in
2002 Range Rover P38 Join Date: Dec 2008
Location: Wigan
Posts: 593
Thanks: 0
Thanked 0 Times in 0 Posts
|
Quote:
FYI: G7IZR 73 & 10-10 Nick Last edited by NikTheGeek; 31st January 2009 at 22:52.. |
|
31st January 2009, 22:26 | #20 | |
Gets stuck in
2002 Range Rover P38 Join Date: Dec 2008
Location: Wigan
Posts: 593
Thanks: 0
Thanked 0 Times in 0 Posts
|
Quote:
Does the ATC illuminate or is it just on, in the background, minding its own business, blowing air in to the car? Or, after all that, do I still have a fault? Its the later 9xxxxx FBH that I have. Mind you, at least when I start the engine and manually turn on the ATC, the air is warm coz the engine is warm! Nick Last edited by NikTheGeek; 31st January 2009 at 22:51.. |
|
|
|