Benm
0
- Joined
- Aug 16, 2007
- Messages
- 7,896
- Points
- 113
You said something like 'they could have just used a resistor', which isnt entirely the case. Lets say they did, and with 3 volts over the diode, and 6 volts supply, that would have been 10 ohms for 300 mA.
Now power this circuit with 12v, still (about) 3v over the diode, but 9v over the resistor, resulting in 900 mA current. It's not quite -that- bad, but its still a rather poorly designed circuit. Then again, as long as you stick to the specified batteries you'll get reasonable performance with acceptable risk. Perhaps they just had a whole lot of somewhat wrong drivers laying around the shop ;p
Now power this circuit with 12v, still (about) 3v over the diode, but 9v over the resistor, resulting in 900 mA current. It's not quite -that- bad, but its still a rather poorly designed circuit. Then again, as long as you stick to the specified batteries you'll get reasonable performance with acceptable risk. Perhaps they just had a whole lot of somewhat wrong drivers laying around the shop ;p