steve1sws Posted June 5, 2005 Report Share Posted June 5, 2005 I have a circuit that I am trying to modify. It is design to operate 110v light bulbs on its outputs. And I need it to work with 12v bulbs in a car (and NOT LEDs). I am NOT a circuit designer, So if anyone can help me I would be very grateful. I would need to know component numbers and what else to modify. The circuit operates on 5 volts. The triacs are TIC206M and the transistors are BC547. The resistors from IC3 to the transistors are 2.2k and from the LEDs to the triacs are 100 ohms. I would like to keep the LED indicaters. I have enough IFR510 MosFet transistors if thay will work. The bulbs I want to use draw about 1/3 amp each. Quote Link to comment Share on other sites More sharing options...
EdwardM Posted June 5, 2005 Report Share Posted June 5, 2005 Hi Stevefirst problem, for me at least, is that I can't read the diagram as the quality is too low, can you post a higher quality image?Ed Quote Link to comment Share on other sites More sharing options...
steve1sws Posted June 5, 2005 Author Report Share Posted June 5, 2005 Yes, I will try to. Steve Quote Link to comment Share on other sites More sharing options...
Shahriar Posted June 5, 2005 Report Share Posted June 5, 2005 Dear steve1sws If if guess right the circuit is Sth. like a Light Dancer. if You meant 330mA for each bulb you can omit those triacs and R15 upto R21 and LD1 upto LD7 and connect the bulbs directly between 12V and Collector of your transistors...If you want to use LEDs instead of Bulbs, you should add some resistor beween the LEDs and Transistor Collectors. For example 560Ohm for Normal LEDs...HTH - Shahriar Quote Link to comment Share on other sites More sharing options...
EdwardM Posted June 5, 2005 Report Share Posted June 5, 2005 Hi Stevethe only thing I would add to Shariars response is a slightly modified power supplyEd Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted June 5, 2005 Report Share Posted June 5, 2005 How about using optoisolators for safety's sake? Quote Link to comment Share on other sites More sharing options...
EdwardM Posted June 5, 2005 Report Share Posted June 5, 2005 Hi Alunhopefully there should be no need to use optos as it's all 12v supplyEd Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted June 5, 2005 Report Share Posted June 5, 2005 Sorry I was looking at the diagram with the TRIACs, of course he wants to convert it to 12V operation. Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 6, 2005 Report Share Posted June 6, 2005 You shouldn't drive a 1/3A lightbulb with a BC547 transistor. When the filiament is cold it will draw a surge current of 3A or more. You need small power transistors. ;D Quote Link to comment Share on other sites More sharing options...
steve1sws Posted June 6, 2005 Author Report Share Posted June 6, 2005 I don't think you guys noticed in my post, I also need to turn all the lights on at the same time. Audioguru did you have a suggestion for the power transistor and how to incorporate it into the circuit. Think to all, For the input. Steve Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 6, 2005 Report Share Posted June 6, 2005 Hi Steve,Use BC368 transistors with 1k base resistors from the Eprom and 1k resistors from +12V to the LEDs. Connect the lightbulbs from the collector of each transistor to +12V.Your Eprom program should be able to turn-on all the LEDs at the same time. ;D Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted June 6, 2005 Report Share Posted June 6, 2005 You shouldn't drive a 1/3A lightbulb with a BC547 transistor. When the filiament is cold it will draw a surge current of 3A or more. You need small power transistors. ;DHow about using power MOSFETs? Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 6, 2005 Report Share Posted June 6, 2005 Hi Alun,You don't need the size, power capability and expense of power Mosfets to drive 1/3A lightbulbs.The only fairly cheap little Mosfet I know, the 2N7000, isn't capable with only a 5V gate voltage. :( Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted June 6, 2005 Report Share Posted June 6, 2005 I should really start reading threads from the beginning before I open my bit mouth. Quote Link to comment Share on other sites More sharing options...
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