Questions tagged [commutation]
The commutation tag has no usage guidance.
17
questions
0
votes
1answer
38 views
BLDC commutation
I have some dilema with commutation on BLDC motor. I have driver for BLDC (MP6540) and I can commutate BLDC motor but motor it is heating up and speed is not appropriate (datasheet says that motor ...
1
vote
1answer
77 views
BLDC motor drive: Requires an external push to start rotating
I am trying to drive a 23-pole pair(i.e. 46 poles) BLDC motor using an LV8139 pre-drive, the output of which is fed to drive the 3 half bridge MOSFETs. I managed to connect the correct phase sequence(...
0
votes
1answer
249 views
Why do the polarities of the capacitor change while discharging?
I was going through the working of class D commutation and the article said:
As soon as the capacitor completely discharges, its polarities will be reversed but due to the presence of diode the ...
0
votes
2answers
146 views
What factors affect a thyristor's “circuit commutated turn-off time”?
In datasheets, they give this value at a certain operation point (voltage, current, and di/dt). My question is... What are the effects of changing these parameters.
For example, if di/dt is ...
1
vote
0answers
33 views
Is zero loss turn-off possible for thyristors?
Consider this very basic circuit:
simulate this circuit – Schematic created using CircuitLab
Don't mind the values - they don't matter, as this question is conceptual.
Imagine that Vcomm is ...
0
votes
2answers
74 views
Looking for reed relays for high voltage commutation
I need to chose a reed relay for connecting a point to high voltage (probably between 7000V:15000V) or to GND signals.
System will have 8 channels (pins). Some of 8 pins will be connected to high ...
1
vote
3answers
92 views
Where exactly appears the channel capacitance and Ron when switch on DG442 switches
I have this switch in a circuit, actually there is 30 switches.
https://www.vishay.com/docs/70053/dg441.pdf
When system is not executing any operation, switches are off. Sx and Dx are not connected. ...
2
votes
1answer
170 views
SSRs influenced by physical proximity?
This is part of a two-head EVSE. The two solid-state relays are used to drive contactors that supply high current power to the vehicles. I used to use a MOC3040 based triac circuit for this job, but ...
0
votes
0answers
100 views
Commutation techniques in SCR
I read in a textbook that "Commutation Time is more in Current Commutation compared to Voltage Commutation".Kindly Elaborate.
-2
votes
1answer
69 views
Newbie question: Feasible way of amplifying 100+ channels of slow and low amplitude signal
I want to amplify signal coming in hundreds of channels (sensor array each producing a very low amplitude 30-200Hz signal). For every channel i care only about intensity of the signal (i don't need ...
0
votes
1answer
999 views
BLDC Motor rotor vibrates with audible high pitch beep, but does not spin. Controlled by custom motor controller
The circuit I have built (taken from the HIP4086A gate driver data sheet found at https://www.intersil.com/content/dam/intersil/documents/hip4/hip4086-a.pdf) is:
The only difference between this ...
2
votes
1answer
180 views
LTspice diode commutation
I have modeled an ideal diode rectifier fed from a 230V/50Hz grid with a slim DC link capacitor and a constant power load (1kW) coupled with a small resistive load. For Cdc=14uF i get a phase input ...
0
votes
0answers
58 views
Commutation overlap symmetry
Let's say we have three phase diode (ignore SCR in the picture) rectifier:
With no source inductance, diodes are conducting at following angles:
Diode 1: 30º < X < 150º
Diode 4: 210º < X &...
0
votes
1answer
48 views
How did rotary converter commutators conduct electricity?
I've been reading about rotary converters and examining photographs, but I've noticed that nearly all have a very strange (to me) commutator design. It looks like a piece of wire screen rather than ...
-1
votes
1answer
70 views
Quick specific questions about Electric Motors that I can't find on Internet
I want to talk about induction motors and Universal motors.
1) is the rotor of an Universal Motor a Wound rotor?
2) the induction motor with Wound rotor have commutators?
3) Universal Motor can ...
2
votes
2answers
1k views
Brushless DC motor problems at high velocities
For a project we use a brushless DC (BLDC) motor. Everything works fine until we tried to reach high velocities. I will first explain my setup, and than explain our problems using some graphs. ...
14
votes
4answers
2k views
H-Bridge Fly-Back
Sorry if this question is a little long, but I though it prudent here to discuss the state-of-the art as I know it before asking the question.
ISSUE
When using an H-bridge to drive a bidirectional ...
