This is the sales thread for the Automotive driver I've been building, and has been discussed here:
http://www.candlepowerforums.com/vb/...-feeler-thread
For those who haven't been following, this driver has high/low/off modes controlled not by a pushbutton or clicky, but by a toggle switch. By connecting the H terminal to C, you get high, and by connecting L to C you get low. Disconnect both and you have OFF. The driver draws about 12 mA in off mode. This could be eliminated by using a double-pole switch.
The high and low settings can be reduced by adding a series resistor in the appropriate control line. This resistor does not carry the LED current, so it can be very small, or even a potentiometer (I've found that 50K linear taper works best, and gives zero to full scale output control. For those who can solder small surface mount components, you can change the settings by changing on-board resistors.
The maximum output can be adjusted using an on-board potentiometer. This pot should not be used frequently for dimming, as it is designed for 100 operations.
PLEASE NOTE: This is a linear driver, not a switchmode driver. What that means is that if the input voltage is much higher than the LED voltage, it will generate a LOT of heat. In most applications it will need to be attached to a large heatsink to prevent overheating. The amount of power dissipated in the driver can be calculated using the following equation:
P = (Vin-Vled) * Iled.
The efficiency of this driver depends entirely on the choice of battery and LED, and the wiring configuration. In the basic configuration, the efficiency can be calculated using the following equation:
Eff = Vled/Vbat
I've written a draft of the data sheet, but it's too large to post so if you want to see it, PM me your e-mail address and I'll send it to you. I'm still interested in feedback on it if you have something to add.
The price is $32.00 each plus postage, prepaid. I use USPS flat-rate box at $5.15 within the US. Most international shipments are a flat $20.00 fee. PM me before ordering if you want it shipped outside the US. You may be liable for import duty or other fees, which can be substantial. Pleas contact your customs office if you are concerned.
I recommend 4-C shielded w/drain cable for remote location of mode switches, pots, etc. Since it's hard to buy in small quantities, I am stocking that too. Price is 1-9 feet, $0.50/ft. 10-49 feet, $0.40/ft. 50+ feet, $0.30/ft.
Payment is paypal (dlburdette 'at' juno 'dot' com). If you want to pay some other way, let me know. Please put your username in the Paypal notes so I can match up posts with payments. Thanks!
There are a few errata for the first production units:
1. The labels for H and C terminals are reversed.
2. Operation of current adjust pot is backward (turn it clockwise and current goes down instead of up).
3. Dropout voltage is <0.3V, instead of <0.2V at 13.5A.
4. Transient suppression is at 85V. I'm going to reduce this so I can use an 85V FET, which will help reduce the dropout voltage.
5. There is no dedicated terminal for the cable shield. It should be tied to the G or B- terminal.
These errata will all be taken care of in the next run of boards.
The following is a list of those who have pre-ordered. They will get priority on the first 20 units, if ordered within a week of this thread going up.
Additional units will be available about 3-4 weeks after the first ones sell out.
I expect to be able to begin shipping by 11/25/12.
mattaus - 2 pcs
mulderfox01 - "a few". I put you down for 2
Trev "Hell yes". I put you down for 2.
DKLaser 3 + some wire.
e015475 - 2 from first shipment, 3 from second.
Tonka truck 2.0 - 2 pcs.
DutchR - 2 pcs.
ktronic - 2 pcs.
Hoop - 2 pcs.
That accounts for 19 of the first 20. However, several of these are from months ago, so I'd be surprised if they all came through.
aurora borealis gcb mary j blige dionne warwick patricia heaton arsenic and old lace leslie
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