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209 Threads found on edaboard.com: Phase Drive
Hi everyone, I am using a PIC18f45k22 chip for Variable phase angle firing of SCRs. I am not using a TRIAC but instead connecting 2 SCRs back to back for commutation and other reasons. I tried doing this with an Random phase Opto Isolator MOC3021. But later got to know that MOC only drives TRIACs... Could any be kind enough in (...)
I still have not received any answer for the question I asked in post #1 Well, the question asks for a decision between two alternatives, but the first is wrong and the second technically impossible. "Constant V/f" actually means that the voltage is varied according to motor frequency, not the other way around. And the simple fac
I opened this new thread because even though this thread is for Three phase Push-Pull signals the method is different that is it uses PWM mode. In the other thread it used Half-Bridge mode. Also this is for Three phase Inverter. The other Three phase thread was for Three phase AC Induction Motor drive. I (...)
Does anyone know of a chip that can drive two steeper motors 1-2 phase (350mA per phase) and another 2-2 phase (350mA per phase) Rather than using two driver ics, I prefer to use one. Anyone aware of such devices - - - Updated - - - drive rate at 4000 and 4500 (...)
You probably have an AC supply at, say, 50Hz. Set up a second supply to drive the gate, at a phase difference of 30 degrees (assuming that is what you mean by alpha=30, and assuming you fire once per AC cycle). If you wish to fire twice per AC cycle, then your gate drive should be 100 Hz at a phase difference of 60 (...)
Hi, Driving a three phase BLDC with sinusoidal voltage will result in sinusoidal currents. Klaus
Hi, We are getting the current from Charge pump and then we converted it into voltage and the again into current. What is the use of this procedure. Are there any advantages. Normally a digital PLL has a phase comparator and an integrator with lead/lag compensation RC network to drive the VCO. Using a charge pump
Lately i've been in need of limiting the RPMs of single phase synchronous motor. I've tried using light dimmer, but it didn't worked out really well. So i've began reading about synchronous motors and VFDs. I understood that you have to change frequency of AC voltage, not it's duty cycle. But commercial VFDs are expensive devices built from expensi
The AC induction motor may be three phase, capacitor start or a shaded pole type. If you need a precise speed, you need to have a motor with built in feedback. Some of them can be used as position sensor. The current fashion is a vfd- variable frequency drive- it works like a charm on three phase drives. They tend to be (...)
Hello everyone, I am trying to build a inverter circuit with inductive load. -input 9V DC -Frequency should be atleast 1MHz. -with 4N(IRF530) mos or preferably 2N-2PMOS. -also i need help with the driver circuit, I am not sure which type to use (pwm,Mu or with logic gates)? and how exactly to built i have not designed so much ever b
hi i am working on 3 phase inverter to drive my 3 phase acim 1 hp. i am taking reference of delta vfd( commercial inverter). for motor control i am using V/F and spwm principle. my problem is motor taking draw sinusoidal current presence of 2 harmonic in motor current waveform taking by CT. please suggest me how i can eliminate harmonics (...)
First, check that the op amp output is trying to do the right thing. Startup is a potential issue, so is swapping phase on the feedback. Next check that for any decent gate drive, the PMOS current sources are capable of pushing the needed current onto the various reference elements. Low value resistor shunts may make booting up impossible. Make
Hello I want to select a relay to drive an air conditioning unit that is single phase and with power about 4.5 Hp . According to calculations, a 30 A rated relay will be enough, but my question is: will it really be enough? I know that Ac machines has starting current that reaches up to 5~7 times the rated current. I do not know what is the r
What should be AC fuse rating & NTC (-ve temperature coefficient) rating for single phase 230 VAC, 50 Hz, 1 KW AC drive (Max input current is 10 A)??
I recently got a azimuth rotator instrument I want to drive, it has a differential synchro in it, 24vdc, both the stator and the rotor have 3 phase windings, usually this device indicates the diference between 2 3 phase signals. I'm thinking if I feed the device 3 phases with 120degree shift between each which works with (...)
Hello i am working on 3 phase ACIM drive. now i have to work on current sense so that motor could not get damage under overload and short circuit condition. my question is which is best method for current sense. 1) Hall effect sensor for AC current measurement at output phase 3) CT current sense at output phase (...)
You could use a PLL with an LC tuned oscillator and Varicap possible and measure the voltage with a coarse adjustment to get the VCO in the sensitive range referenced against a fixed OSC at the highest practical resonant frequency. Otherwise you can drive a fixed frequency and measure the phase shift with L in a tank circuit with high Q to improv
I am planning for a drive using 6 lead stepper motor voltage is 12 V Winding Resistance is 25 ohm. ULN 2003 or ULN 2803 seem to be insufficient in terms of total power handling capacity. Any advise for a suitable d
It is rated for 4~8 Ohms so wiring speakers in parallel series to match within this range and proper polarity or phase is required. Do you know each speaker impedance? can you do this?
Can Someone please give me a circuit design for a Single phase VFD, emphasizing that it shoudn't be a 3 phase circuit.