gaeasNavel Posted September 13, 2006 Report Share Posted September 13, 2006 can anyone tell me how to amplify the voltage.. say, in a ciruit i have a 12 volts supply for it and because of voltage drop when it reach to the last device which is a relay(12), the relay would not function properly anymore.advice much apprectiated.. Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 13, 2006 Report Share Posted September 13, 2006 A circuit to boost a DC voltage is complicated.What is causing the voltage drop in your circuit? If you use a transistor to turn a relay on and off then its voltage drop will be only about 0.2V. Quote Link to comment Share on other sites More sharing options...
gaeasNavel Posted September 14, 2006 Author Report Share Posted September 14, 2006 i really dont know... coz ive tried to make an object avoider and ive used a relay for the motor to reverse, but since im using a relay(12v), after ive run the circuit the relay wont work properly, my circuit has only 3 sensors, 3 basic gates, a transitor to switch the relay, but still the output voltage going to the relay drops down from 12 volts to 5.... I really dont know what happen.. Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 14, 2006 Report Share Posted September 14, 2006 after ive run the circuit the relay wont work properly, my circuit has only 3 sensors, 3 basic gates, a transitor to switch the relay, Quote Link to comment Share on other sites More sharing options...
gaeasNavel Posted September 15, 2006 Author Report Share Posted September 15, 2006 This is the schematic... ive only made it on paint... thats an object avoider circuit which ive made it on my own, the relay's used is for the motor to reverse, but i could now make the relay work properly, any ideas how did my circuit gets wrong.. Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 15, 2006 Report Share Posted September 15, 2006 Instead of drawing a relay with a coil and contacts, you drew a box with 4 wires. So I don't know which wire does what.It looks like the transistor is giving the relay coil about 4V (maybe not enough voltage for a 6V relay), and the motor is fed 3V from the relay contacts. The relay coils don't have a reversed diode across them to arrest the high voltage spike when they turn off, so the transistors and maybe the ICs are destroyed.The circuit doesn't have a 12V power supply like you said. Quote Link to comment Share on other sites More sharing options...
gaeasNavel Posted September 16, 2006 Author Report Share Posted September 16, 2006 i really dont know what a relay looks like inside, and i dont know how to draw its schematic, thats why ive only draw a box, it has 5 wires, sori for the newbienez... Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 16, 2006 Report Share Posted September 16, 2006 There are lots of ways to draw a relay. Datasheets for relays have their schematic symbol.I copied this one from one of our projects: Quote Link to comment Share on other sites More sharing options...
MP Posted September 17, 2006 Report Share Posted September 17, 2006 In looking at your schematic, it seems that you are powering and also grounding your motors through the relays. Perhaps I misunderstood which lines were which. However, if this is the case, I would advise that you use a permanent ground or permanent voltage connection and only use the relay for the other lead. You only need to disable one connection to the motor to stop it from running. This will reduce some arcing in the relays and the circuit will last longer without the need for maintenance.Next, you should probe the circuit from the motor back to the digital circuit to see where the voltage loss becomes apparent. I would use a better design for the transistors used as a switch. Look closely at this area when you are probing. MP Quote Link to comment Share on other sites More sharing options...
audioguru Posted September 17, 2006 Report Share Posted September 17, 2006 It looks like the relays are wired to allow the motors to reverse direction. There is nothing on the schematic to turn the motors off. Quote Link to comment Share on other sites More sharing options...
MP Posted September 21, 2006 Report Share Posted September 21, 2006 gaeasNavel, I have sent you a file by email at your yahoo account.MP Quote Link to comment Share on other sites More sharing options...
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