# Tag Info

## New answers tagged voltage

1 vote

### How to check output voltages?

Judging from the bits that are truncated to the right in that service manual you copied, the right hand connector is numbered 1..12 from top to bottom like the other connectors (also notice the three ...
• 331k
1 vote

### How to check output voltages?

Although brhans is right, you can still find the voltages by simple continuity checks: It should be easy to find the GND/return of DC outputs because it's common for all. Find C881 on the board and ...
• 17.4k
0 votes

### Amp and voltage effect on solenoid coil

The term used for determining the magnetomotive force of a solenoid is "ampere-turns" which alone should answer your question. Think of it another way: your solenoid has a given resistance, ...
• 27.6k
0 votes

### Amp and voltage effect on solenoid coil

The solenoid coil has a certain DC resistance, R, that depends on its construction (mainly the gauge and length of the coil wire). Ohm's law then determines the relationship between voltage across the ...
• 15k
0 votes

### Amp and voltage effect on solenoid coil

Solenoids have very low DCR. The battery is expected to have much lower ESR so the voltage does not drop significantly and this resistance decreases as the Ah rating increases. Without any details I ...
0 votes

### What circuit for the following input and output?

The logic derived from the drawing is that from every third transition, output a negative pulse approximately 50% of the clock rising edge interval. This could be made more precise if there were ...
0 votes

### Add symmetrical deadtime in PWM

This deadtime CMOS Logic could be performed in BJT or TTL logic as long as you are aware of how this circuit works and its shortcomings. The deadtime is chosen with a discrete RC circuit and utilized ...
2 votes
Accepted

### Ethernet differential signals

Probably not. The result is less terminated, of course, giving more crosstalk between symbols. It's only 25% more, while the signal levels are +/-50% so to speak, so it should still work say with a ...
• 2,753
2 votes

### Ethernet differential signals

No. Ohm's law says same current through different resistance causes a proportionally different signal voltage. Yes. Chips intended for muxing Ethernet do exist.
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1 vote

### How much voltage does a farm electrical fence really output?

1 mile of wire >1 foot above ground has roughly 10 nF of capacitance. The capacitance along with the output impedance of the device will attenuate the output voltage. There will also be leakage ...
• 4,058
-1 votes

### How much voltage does a farm electrical fence really output?

13KV is the unloaded (open-circuit) voltage. Lets assume that the source has some unknown source resistance R1. Lets also assume that 3 miles of fencing loads down the source with R2. simulate this ...
• 9,735
-2 votes

### Is single PWM kind of AC voltage?

Ok, AC means signals (current or voltage) jumping across zero; whereas PWM is DC (current or voltage) switched ON/OFF at desired time interval, non-zero crossing.
0 votes

### Is 7.4 V safe to power servo motors?

A Lithium-ion or Li-PO battery cell averages 3.7V during a discharge. It is 4.2V when fully charged. It should be disconnected at about 3.0V. A Ni-MH battery cell averages 1.25V during a discharge. It ...
• 2,417
3 votes

### Is 7.4 V safe to power servo motors?

it will be safe for servos? The specs say that the maximum allowed voltage is 6V. So no, it will not. The motor itself may survive but the servo section (i.e. controller board/sub-circuit) may not.
• 17.4k
1 vote
Accepted

### Question on Resistor and Capacitor Arrangement & Power Supply

... Higher capacitance on the power rail should not be a problem, right? Depends on how high the capacitance is. For linear regulators higher capacitance is not always good as it may cause ...
• 17.4k
3 votes

### How to optimally decide modified square wave duty cycle for an inverter?

There are several considerations that govern the determination of an optimal duty cycle. Firstly, so that resistive loads work with no modification in power, the RMS voltage of the modified square ...
• 1,041
2 votes
Accepted

### How to avoid square wave parasitic oscillation?

Your design has the wrong threshold to act as Schmitt Triggers on slew-rate limited pulses in order to create "complementary-exclusive transitions" or a "deadtime control circuit." ...
1 vote

### Average voltage in PWM?

If you have a simple first order RC filter which removes PWM switching frequency but leaves the DC voltage, it has the correct output voltage, but due to the resistor, the output impedance at DC is ...
• 89.6k
0 votes

### Average voltage in PWM?

In every DC-DC (buck) converter you will find an inductor that is connected in series to your PWM output and a parallel capacitor that is connected to the inductor output and ground. Together, these ...
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9 votes

### Is twisting a single ended signal with its own GND really useful?

It strongly helps when done right. Allow me to make a small story arc to explain my answer. The problem Ground planes are good dump-and-forget nodes for return currents at both high and low frequency ...
• 10.9k
6 votes

### Is twisting a single ended signal with its own GND really useful?

We can distinguish two kinds of coupling, inductive and capacitative. Using balanced twisted pairs helps reduce inductive coupling. But the question is about unbalanced twisted pairs. It turns out ...
• 13.1k
19 votes

### Is twisting a single ended signal with its own GND really useful?

Yes, it is better. Model the cable as two transmission lines: one representing the differential mode (signal to GND wire), stacked on top of one representing the common mode (GND wire over GND plane)....
• 2,753
0 votes

### How to light one or some LEDs with extremely low current?

With a classic bridge rectifier we only catch the enery peaks. This has a bad power factor. I have difficulties to simulate such an energy source, but I assume, that any change in charge should be ...
• 1,924
1 vote

### Can the current through a connector be higher than the rated current at lower voltages?

The answer, in most circumstances, is no. This current rating is the connector contact’s current limitation, i.e. the maximum current the connector contacts can withstand. Please note that current ...
0 votes

### How to light one or some LEDs with extremely low current?

After reading the Wikipedia article on triboelectric nanogenerators, it looks like you will need to capture and store the pulses of power generated by the your gadget. Rectify the pulses, store the ...
• 58.3k
0 votes

### How to light one or some LEDs with extremely low current?

The circuity is tricky since the current are very small. Luckily there is a whole sub-industry dedicated to this kind of applications. Search for "energy harvesting". The usual major ...
• 7,676
2 votes

### Ethernet transformer

In transformers, we distinguish between excitation current and magnetizing current. The excitation current represents energy passed from primary to secondary. The magnetizing current represents energy ...
• 1,611
5 votes

### Ethernet transformer

Ethernet is a digital signaling standard. Pulses must be sent and received, over a modest distance (~100m), without consuming excessive power, avoiding random errors, and tolerating ambient noise (...
• 2,753
3 votes

### Ethernet transformer

Can someone tell me what is the meaning of Open circuit inductance That's the inductance of a winding when all the other winding(s) are left open (Similarly, the inductance measured when all the ...
• 17.4k
0 votes
Accepted

### Is it safe to discharge li ion below 2.5v?

Li-ion cells usually work in the range of 4.2V (while charging) to 3V (fully discharged). This voltage range MIGHT differ depending on the manufacturer and their cell chemistry. But this is a general ...
0 votes

### What voltage to charge a single NiCd cell?

You don't use input voltage as the metric for charging NiCd. Best results are gained by discharging to 1 V/cell, then charging at constant current of 0.1 of the A-hr rating for 16 hours. That is, if ...
• 58.5k
1 vote

### Conversion from 0-10V to resistance - Methodology

If you have PWM, you can be synthesizing a resistance directly. All you need is an analog switch, like a 74HC4066 or CD4006. Parallel all switches in the package, and add an external resistance that ...
1 vote
Accepted

### How to detect welded contacts of a redundant relay? (for reliable high-current e-Stop)

Interesting question. Although DPDTs are challenging to find in the VDC and current ratings you require, automotive SPDTs are readily available. With those, you can do the following: simulate this ...
• 10.5k
1 vote

### Is there a way to predict the VDC rating of a relay in function of its VAC rating?

The only thing you can say for certain about the DC rating of a relay is that it will be less, much, much less, than its AC rating. There are various features the relay designers can use to increase ...
• 142k
1 vote

### How to detect welded contacts of a redundant relay? (for reliable high-current e-Stop)

(I misunderstood the question to start with, but I think the answer to that could still be useful, so I'll leave it up, below the break.) Answer to the correct question: There are contactors with ...
• 5,356
2 votes

### How to detect welded contacts of a redundant relay? (for reliable high-current e-Stop)

You could do something like this: simulate this circuit – Schematic created using CircuitLab One 14-pin jellybean chip, a few resistors or networks and one LED. OA1 and OA2 form a window ...
• 331k
1 vote

### How to detect welded contacts of a redundant relay? (for reliable high-current e-Stop)

Have an "off light". Remember, the "stuck contact" condition simply cannot be detected while the machine is intended to be on. Use DPDT relays. On one pole, use the NO contacts for ...
1 vote

### How to calculate the scale factor of non-linear ADC output value?

So you have a scale and zero error. V = 1.019*ADC_READING + .047mV, based on the points above. Chances are the best gain factor is somewhat different from 1.019- to get an accurate factor, pick points ...
• 331k
0 votes

### Why are there two NOT gates in a complementary PWM circuit?

Always be mindful that digital electronics is merely convenient analogue electronics. The AND gates have an analogue voltage range, consisting of two digital regions (valid logic LOW, valid logic HIGH)...
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3 votes

### Why are there two NOT gates in a complementary PWM circuit?

The RC circuit will not produce a clean digital pulse. The edges will be rounded. Your drawing shows the rounded corners of the output of the RC circuit. The first NOT gate (actually a Schmitt ...
• 58.3k
2 votes
Accepted

### How to calculate the current through the LEDs/the collector current in the BJT circuit

Assume beta is large, base current is negligible. Assume ideal zener diode: if current flows through it in reverse, it will deliver the voltage on the label. So, there's 4.7V across the zener, and the ...
• 59.4k
2 votes

### In a DC voltage sensing circuit, what's the need for capacitors on input and output?

If the input signal is always DC, why do I need these capacitors? Alas, the input signal is usually not DC, because various source of interference superimpose their own AC currents on top of the DC ...
6 votes

### In a DC voltage sensing circuit, what's the need for capacitors on input and output?

C22 may be useful if the DC input voltage contains an AC ripple or noise, that needs filtering. C23 at the OpAmp output is not a typical design. Many OpAmps can not drive such a capacitive load and ...
• 1,924
2 votes

### SPI MISO line not working

One classic mistake is that when you connect two live, supplied boards and the TTL level signals connect before ground pins, something else might become ground temporarily, resulting in wrong voltage ...
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0 votes

### AC coil heater vs DC coil heater - efficiency improvement

Switching AC with semiconductor devices is not fundamentally more complex than switching DC. Usually you just need two mosfets instead of one, for example. Or use a triac – a very robust device. ...
1 vote

### AC coil heater vs DC coil heater - efficiency improvement

AC power is like a trusty work-horse. DC is like a rhinoceros. AC power is easy to manage because it reverses polarity 100 times a second, which means you have a zero-crossing for voltage and a zero-...
0 votes

### AC coil heater vs DC coil heater - efficiency improvement

As Dandavis said, moving to DC will be less efficient because some power will be lost in heating the rectifiers and other components. Replacing the relay with a triac or other electronic switch could ...
• 59.4k
0 votes
Accepted

### Dependent source circuit find voltage

You need to introduce $I_M$ into the fray or you'll just get 0 = 0 and that helps nobody: - $$5 = 2\cdot I_M + V_A$$ Where $V_A = 2\cdot I_M$ (as per the dependent source) so: - 5 = 2\cdot I_M + ...
• 384k
2 votes

### Converting pressure to voltage

You don't need to calculate anything. You need to read the manual as Jonk said and set the parameter OU2 to voltage and measure the voltage between pin 2 and 3. The parameters AES and AEP sets the ...
• 3,480
0 votes
Accepted

### Does the direction of coil winding impact the direction of induced voltage?

For anyone, who is interested in the answer, I opened a question about it at physics.stackexchange.com. You can find the answer here.
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