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9 votes
Accepted

Is the resistor between the clock and the NPN needed?

R1 has two purposes. Without R1 current flowing from clock generator output to transistor base to emitter to ground will be limited only by clock generator itself. But even if it's not a short ...
Matt's user avatar
  • 241
5 votes
Accepted

Why is my inverter circuit outputting this waveform?

Your high side MOSFETs are N-channel, so you need gate voltages above 12 V to turn them on. Presently, your opamp which drives them are driven from the same 12 V rail so they can't turn on. Either you ...
winny's user avatar
  • 15.4k
4 votes

Is the resistor between the clock and the NPN needed?

R1 limits the current through the Q1 base-emitter junction to a value that is safe both for the transistor and for the oscillator output stage. Like most diodes, a transistor base-emitter junction ...
AnalogKid's user avatar
  • 20.7k
3 votes
Accepted

Unexpected output distortion when driving MOSFETs with SPWM in LTspice

We want to reduce the gate voltage of the high side FETs to the source voltage, not necessarily ground. If I had to take a guess at the immediate issue, it may be that. I have a problem with a few ...
theph's user avatar
  • 176
3 votes

Is the resistor between the clock and the NPN needed?

The short answer is yes, you need the resistor. However as noted in comments, this circuit won't really work over the range 1-14MHz, in fact it barely works at 1MHz:
Spehro Pefhany's user avatar
2 votes

Battery-Inverter-Converter Circular Flow

Sounds like you want to do this: simulate this circuit – Schematic created using CircuitLab
MOSFET's user avatar
  • 4,000
1 vote

How do i make PWM be in the middle of the other one

How do I get it so that the 2nd PWM rise and fall while the 1st PWM is off like in this image Very much more simply by using a single channel of PWM and an anti-shoot-through circuit like this: - ...
Andy aka's user avatar
  • 460k
1 vote

Will I die or get a decent shock using an inverter?

Think about it for a minute... If you grabbed the live or the neutral wire you would get a mild electric shock but the only return current path is the few pFs of capacitance from you to the inverter ...
Voltage Spike's user avatar
  • 83.4k
1 vote

Voltage drop in NMOS inverter with enhancement load

why is the voltage drop across M2 at least equal to Vth when VIN is low? For M2 to turn on, V(GS) needs to be Vth or more, per definition of Vth. Since M2's gate and drain are connected together, ...
Kuba hasn't forgotten Monica's user avatar
1 vote

Unexpected output distortion when driving MOSFETs with SPWM in LTspice

Usually its the parasitics in the FET models. You can replace your FET model with ideal voltage controlled switches to double check. You can try putting a gate-source resistor on the high side FETs to ...
Gswffye's user avatar
  • 156
1 vote
Accepted

Why does inverter malfunctions when PCB is placed near metal enclosure?

Responding to your comment: "Resistor besides R26 is short circuited to disable over current trip of MOSFET driver." It seems that the controller chip is sensing an over-current condition. ...
Fabio Barone's user avatar
  • 4,084
1 vote

Preventing spikes in inductor current (probably) caused by lab power supply

These are not spikes in inductor current (you can't get those with 12V available -- consider V=L.di/dt). Likely you are picking up stray signals across your 8.9 Ω (strange value) R. To confirm this, ...
jp314's user avatar
  • 19.1k
1 vote

Invert polarity of an input

We need to agree some terminology. In most electronics we have a reference which we call ground or GND. Voltage readings are taken with respect to GND. On your motorcycle the chassis is GND as the ...
Transistor's user avatar
  • 177k

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