11
votes
How the slew-rate and drive strength affect the output signal of the FPGA?
As its name suggest, the slewrate preference is a preference for the rate of change of the signal at the Output Pin. Though seemingly unrelated, this is coupled with the load preference (which limits ...
- 320
11
votes
Accepted
Design of very long serial signal systems
Software
In software (regardless of the hardware chosen), you basically want debounce code which ignores transients.
There are endless algorithms, but perhaps one that is suitable is:
sample at high ...
- 16.2k
6
votes
How do DVD players know how fast to spin?
How is the disc playback rate determined?
CDs and DVDs use a recording technique called Constant Linear Velocity, or CLV. The pit-and-land data on the disc have a channel coding rate for the raw ...
- 58.2k
5
votes
Accepted
LED resistor on 3.3V source - what happens to LED current/voltage drop?
The tricky thing about LEDs is that they are current driven rather than voltage.
Your LED datasheet has this chart:
You could read it as "for voltage X, current Y will flow through the LED."...
- 73.5k
4
votes
Make a DVD drive turn the other way around
TL;DR: Just reversing the direction of the motor does not help - the disc dictates the direction.
If one manages to let the motor run backwards, writing a disc might be possible on the first view.
...
- 8,670
3
votes
Accepted
Connecting a three phase drive - Should N connect with L3?
The L1, L2, and L3 markings are for using three phase power.
The L and N markings are for using single phase.
You are using three phase, so ignore the L and N markings.
For three phase, the controller ...
- 73.5k
3
votes
Accepted
Does max OP Amp Capacitive Drive Capability Matter with Active Filter?
The stability issues with driving a capacitive load with an op-amp have to do with a capacitive load to ground.
Basically, without feedback a typical op-amp has an output impedance of hundreds of ohms ...
- 47.1k
3
votes
Accepted
Is Modbus suitable for motion control positioning?
TCP/IP based systems are not real-time systems. There are no guarantees that packets will arrive in a timely manner, or at all. Therefore it is considered unsuitable for real-time control. As for the ...
- 22.2k
3
votes
Is Modbus suitable for motion control positioning?
Have a look at the CiA 402 specification. It's a widely adopted (at least in Europe) standard for drives and motion control.
We've implemented several CANopen and EtherCAT servo drives using the CiA ...
- 4,692
3
votes
Which part on the circuit board has the software or firmware?
The picture of the PCB shows the obsolete Texas Instruments TMS320C32PCM40 DIGITAL SIGNAL PROCESSOR. The datasheet shows there is no user programmable internal non-volatile memory, so the program for ...
- 7,163
2
votes
How does a DC motor drive control the motor?
It doesn't drive the motor. I assume you're talking about a brushed DC motor. Brushed DC motors have the commutation built into the mechanics of the motor - the brushes are part of that. You can ...
- 485
2
votes
Apart from speed, do VSD's also alter current?
VSD stands for variable speed (DC or AC ) drive.
A VFD is a DC controlled Variable Frequency AC Drive.
Modern VFD's are highly programmable to sense RPM, current and control V/f with PWM. There may ...
- 148k
2
votes
Fail safe led circuit
simulate this circuit – Schematic created using CircuitLab
User Choices
LED Off until initialized as output with value = "0" ,
May be inverted to 1 = ON with LED cathode to 0V an 1k to Anode....
- 148k
2
votes
Accepted
Meaning of "Supply Voltage: 3~132V" on an electric drive system plate?
Let's cross check everything.
Output speed in rad/sec:
85 RPM * 1m/60s * 2 * pi rad/rev = 8.9 rad/sec.
Output torque: 190 Nm.
Output power: 190 * 8.9 = 1.7kW
Input power (assuming it is three-phase):
...
- 29.5k
2
votes
Can I use a .75 HP inverter drive in place of a .5 HP one?
You most certainly can.
Don't forget to lower the nominal motor current setting in the inverter though.
- 121
2
votes
Accepted
How to implement the design of a bidirectional buck-boost converter?
You need to choose a switching device that looks like it has a prayer of working
From comments: -
G2R120MT33J That the Mosfet. I am using. – victor_uk
Here's the safe operating area from the data ...
- 473k
2
votes
Cascading opamps to drive a MOSFET
1 microvolt on an output voltage range of 10V is 0.1ppm. That's firmly in the 7.5-digit voltmeter territory. Whatever you're getting from SPICE for such requirements is pure fantasy, since in an ...
2
votes
Does max OP Amp Capacitive Drive Capability Matter with Active Filter?
Don't have ADA4523 in the database.
Will use another op-amp like ADA4062-2. Don't checked if "equivalent". (not really).
For reference, here is a simulation showing the currents through the ...
- 15.7k
1
vote
Accurate Static Pulling (with electric motor?)
This is a fairly common thing to do with electric motors. Essentially you need to control the motor's current. The current is proportional to torque using a constant called the torque constant \$K_t\$ ...
- 536
1
vote
Accepted
Is it possible to have a 2-in-1 USB device that is a Flash Drive and Power Bank?
Power banks typically are USB hosts so they can negotiate about voltage and current requirements with connected devices and e.g. cut power if required. In contrast to this, a USB flash drive (aka &...
- 2,923
1
vote
Accepted
What micro-controllers are suitable for a closed-loop DC Motor?
Assuming a brushed DC motor, if you're planning on tachometer feedback a quadrature encoder peripheral would be a good thing to have. On-chip ADC may or may not be adequate for the analog inputs- ...
1
vote
Avoiding RCD tripping with Inverter Drive
Although dangerous, hypothetically, would removing the Earth
connection from the drive solve the problem? In doing so, there would
be no current leakage down to Earth.
The possible (or even ...
- 473k
1
vote
Fail safe led circuit
If LED will be placed outside of your PCB, there is always risk of get any voltage spikes via LED wiring into the circuit - and this may damage the IC. In case that you use additional driver (...
- 1,588
1
vote
Accepted
Fail safe led circuit
Out of interest would there be ANY reason at all to choose for circuit
3 over circuit 2? I see none.
I would also consider circuit 4: -
Circuit 4 allows P1 to clamp the LED anode to about 0.7 ...
- 473k
1
vote
High Impedance Load Driving with Mosfet as Common Source Configuration
\$I_{DSS}\$ is the drain source leakage current when the gate is tied to the source and, for the IXFX90N30 at 25 degC this is 100 uA. Of course that 100 uA will appear as an AC signal but, assuming ...
- 473k
1
vote
Accepted
Colpitts / Clapp oscillator crystal drive level
The initial gain of the circuit is essentially what drops out of the small signal model -- some perturbation of the voltage or current at some point of the circuit will result in some perturbation of ...
- 47.1k
1
vote
Colpitts / Clapp oscillator crystal drive level
It depends on gm*Re of FET and ESR of Xtal to achieve reliable oscillation and startup.
adding Rs =X is a good way to measure this gain margin and but to limit current to some extent, add an R ...
- 148k
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