![]() ![]() This leads to uneven motor speeds while trying to go straight and would be a great time to use the integrated hall effects sensors. Mine are around 0.6-0.7V at max throttle. This means finding a set that has similar voltage drop across the output terminals and lower is better for heat buildup. I also was unable to achieve proper tank steering function in my previously mentioned instructable.Ĭ) The SSRs are not a great quality and need to find a "matching" pair to use together. ![]() I have done a few test runs and have done fine with no delay and some abuse.ī) I programmed Elevons/Tank steering in my transmitter to make my arduino program simpler. Then each relay would be designated for the modulated voltage signal or ground/return from the motorĪ) Don't be a stick slammer with the transmitter joysticks or you will run into an issue not having a delay when your 12V relays change states. ![]() I would want to trigger both at the same time with 24V and would put the coils in series. I kept looking for a suitable relay and came up with the idea of using two 12V single-pole double-throw (SPDT) relays. I quickly found out that these relays are expensive for a 40A load. What if I effectively modulated the input voltage for speed control but switched my motor wires when I wanted to go backwards? This is where I cut out three SSRs per motor and wanted to add a 24V DPDT relay. The third idea came while I was waiting for the SSRs to arrive from China where I saved $4/ea versus ones already in the USA. I then placed an order for 10 SSRs from the wonderful Ebay. You can also feed them a PWM signal to control the speed of the motor. SSRs have internal circuitry/magic that makes it possible to use 5VDC to trigger 24VDC. My second idea, was using solid state relays (SSRs) in an H-bridge configuration. I was kind of lazy and making circuit boards can be expensive. I didn't want to design a circuit board and go through the additional complexity of driving MOSFETS. This is where a charge pump comes in, but that is where I took a detour. I found out that you can't use 5VDC to trigger 24VDC on the high side of the bridge. I first tried building an H-Bridge using N-channel MOSFETS. When you have success you will know where it came from instead of saying "I don't know it just works now!?" This makes it easy to identify your mistakes so you can turn around and have a success that you learned something. _ | | | author : Philippe de Craene AC output rectified voltage sensor A1 => DC input current sensor ACS712 20A A2 => heatsink temperature sensor LM35 A3 => battery input voltage A4 => LCD 1602 SDA A5 => LCD 1602 SCL 4 => disable: SD pin of IR2184 (AC output driver) 8 => DC to AC phase 1 with IR2184 9 => DC to AC phase 2 with IR2184 10 => DC to AC phase 3 with IR2184 3 => 12VDC to 400VDC with IR2011 11 => 12VDC to 400VDC with IR2011 12 => synchro output (for oscilloscope external trigger) 13 => activity / alarm LED output Versions history - version 0.5 - 20 july 2020 - first operational version version 0.6 - 50Hz starts once Vht is raised */ #include // #include // // Parameters //- bool SETUP_MODE = false // read the Ioffset value needed for 0 current bool VERBOSE_MODE = true // set the console display mode const int Ioffset = 565 // set to get 0 when no current (mid value 0-1023 const float coefVht = 1.26 // calibrate the output 2 phases AC const float coefVbat = 0.97 // calibrate the input DC voltage const int microseconds = 3333 // AC period => 3.33ms for 300Hz = 6x 50Hz const int VhtRef = 200 // 200V DC gives 192V AC const int deltaVht = 4 // tolerance/hysteresis on Vht const int VbatMin = 11 // inverter will stop below this input voltage const int VbatMax = 29 // inverter will stop after this input voltage bool isThsSensor = false // is there or not a temperature sensor on IRFB4110 heatsink const int ThsMax = 70 // heater sink max temperature bool isIdcSensor = true // is there or not a current sensor in use const int IdcMax = 10 // absolute max current from DC input => 10 = 10A // choose the right current sensor model for ACS712: //float convI = 185.0 // 5A ACS712 module => 185mV/A float convI = 100.0 // 20A ACS712 module => 100mV/A //float convI = 66.Everyone gives me a look when I tell them to set themselves up for failure before success! In short, take notes on what you are doing, changing, or breaking. * Mini inverter for a 230Vac 50Hz from a 12V ro 24 DC, for a power up to 500W. ![]()
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