General Q&A about the design and function of electronic systems, electric power systems and infrastructure, their theory, and tools specific to those fields. Read these guidelines before posting.
Filters (None)
I am using two 18650 cells in series to power a RC car. Is the voltage goes below 6.2 V, the battery should be disconnected to prevent over discharging the battery. At the same time I want to imple...
When recording an ECG signal, the raw signal is taken from the body and sent into an ECG amplifier to amplify the signal to a suitable range and remove common mode and other types of noise. Measur...
Design a suitable experiment and an AC circuit to verify Thevenin's theorem when the load is a single-phase induction motor with a capacitive start and two supplies feed the load. Ratings of load:...
I have been observing these little cases hanging to the wires from a long time. They are almost everywhere here in India, but I was unable to find out what they are. I am not sure whether they are...
A full wave rectifier converts a sine wave to DC pulsed signal of double frequency. Is there a circuit which does the reverse process?
I need a Sine Wave Oscillator circuit that can allow me to control its frequency with a microcontroller. Until now all the topologies that I have found if the frequency is changed, a change in the ...
I have the following problem: - Using Wikipedia I find that during CCM we have the relation: - $$\frac{V_{out}}{V_{in}} = -\frac{D}{1-D} $$Solving for $D$ and inserting values gives me $$D...
I have recently finished designing a buck-boost converter for a job that uses a split (+/-) input power supply. Load power is taken equally from both positive and negative input supplies and, the ...
If I connect a battery to an LC tank and then to an antenna and then on the other side at a distance x, I connect an antenna to another LC tank and this to a diode and this to an LED, Do a I have a...
I am working on routing a microprocessor to two identical single data rate (SDR) SDRAM chips that are PC166 compliant, particularly Alliance AS4C16M16SB-6TIN. The 16 bit SDRAM chips are combined t...
I am designing a 4-layer PCB that has both analog and digital circuitry throughout it. The analog section involves high return currents as well as ADCs sampling the voltage across sense resistors a...
I was watching this video by w2aew on the function of ceramic bypass capacitors, and at 6:00 he states that high-frequency currents take the path of least-impedance and make their way to the power ...
A differential amplifier amplifies the difference between the two input voltages but suppresses any voltage common to the two inputs. Based on this scheme the differential amplifier is substrac...
More about the circuit The circuit is sensing (low side sensing for many reasons) current used to power up the lights with 28V(part of the schematics not shown here -> relay with LC filter ...
In this circuit below the relay circuit part is acting as an inrush current limiter, but I can't understand how it works since the current is flowing in both conditions where the relay is open or c...
I have an mcu pin and I want to sense a voltage up to 24V to 36V. I want to connect some outputs on the board I'm designing and I don't know whether those outputs will provide a voltage or will be...
Hi guys so recently i was looking for a mosfet and a gate drivers and between a lot of their specification the rise/fall time and Turn-On/off Delay Time sometime it called propagation. My question...
Based on this paper on Wiki a diode can be described as a frequency mixer due to the exponential relationship between current and voltage.What I don't get from which point to which point do we meas...
Suppose we have this circuit which is supposed to be an unbalanced frequency mixer. But how does the diode generate a signal with new frequencies at the output?
I've seen a few different circuits (a) (b) (c) (d) described as "an O-ring circuit" or "an optimal O-ring circuit". What does the "O" and the "ring" refer to in such circuits? How do "O-ring circ...
We identify semiconducting electrical components this way: The first digit represents the number of pn junctions inside the semiconducting device The two or more digit number starting at position...
If we a varactor and we want to control let's say the resonant frequency of the circuit ,in my schematic we must add R1 correct?Else we create a low resistance path for current to flow not through ...
Which are the parameters I should looking for when picking a flyback diode to be placed across a generic coil, such as a relay? That is: a coil with plain on/off functionality, for example a 24VDC ...
I've accidentally burnt my dimmer with a short. It is a common dimmer with a triac/diac/pot of the simplest configuration (the triac is a BTA16). After replacing the triac, this still does not work...
This application note from Linear Technology discusses oscillations in opamp circuits and some compensation schemes. One method discussed for reducing phase shifts in the loop gain due to the RC ne...
I am designing a PCB that has to have class 1 div 1 associated apparatus (only the outputs to the sensor) certification. Essentially, I am using a boost converter to convert the voltage from a lith...
I have seen pi-filters using chokes, ferrite-beads, and plain inductors as the L-element What are the main differences between them? when use one or other?
My question is trying to understand if there is an effect on the switching time, on both turn-on and turn-off, between the following configurations. A mirror set up to switch a current, and there ...
What is your best suggestion for building a follower that would ideally satisfy the following spec: frequency: from 100 Hz (or lower) to 1 GHz input signal impedance: 1 Mohm input signal ampli...
I am calculating the base current of transistor Q1. To simplify the circuit equations, I applied the Thévenin's theorem twice and converted V1, R1 and R2 into Vth and Rth, as shown in the image. ...
I am analysing a pulse transformer which is required to transfer below communication protocol pulse from primary to the secondary side. The pulse duration is 32 μs and off time available to reset t...
I am trying to analyse what is controlling the load current in the below Darlington configuration. Is it the base current of transistor Q3 which is controlling current through R14 / emitter curr...
It is common to have a series resistor to limit the current trough an LED. I saw a circuit using the LED driver: stp16cpc26. but instead having the series resistor, they are in parallel. This LED...
I'm trying to modify a LED torch, and there is a DC-DC booster (1.5 V to 3.3 V) and after that some SOT-23 device which (I assume) keeps constant 90 mA current through LED. I know I could remove th...
I see a lot of common collector amplifiers with the output taken across an emitter resistor. What is the purpose of doing it this way instead of connecting your load directly to the emitter? I sh...
Suppose we have this circuit How do I pick a appropriate value for the resistor R1?
In both cases, is the "X" point floating when there is no 12V applied ?
I have been trying to model this oscillator I was wondering if we can somehow predict the frequency of the oscillations.For small currents inside a diode from the Shockley diode equation $$ e^{x...
The current through the tunnel diode is: where $I_{f}$ is the current from the Shockley diode equation and $I_{tunnel}$ is the tunnel current. Is there an expression for the tunnel current or i...
I am trying to understand tunnel diodes by experimenting with them. Research tells me they can have negative resistance, and can be used to build a high frequency oscillator. Tunnel diodes are su...
I am looking at various DC/DC converter topologies for a power system I am designing. The most suitable topology for me is one that can perform both step-up and step-down functions, so I am looking...
Hi guys,I'm designing a multiple output flyback converter with 2 outputs at 10v@1 Amp and 5v @ 2 Amps .Input is 20 V dc Im having some problem with the implementation of closed loop. Open loop res...
Instead of using a buck or a boost converter can we use for DC-DC conversion the circuit Im going to describe in the next lines? First we begin with a Hartley oscillator whose output is fed into ...
In the field of DC/DC conversion, one can build a synchronous DC/DC converter (also referred to as synchronous rectification). This practice involves replacing a diode with a MOSFET switch. As far...
I want to run a specific motor in the open loop. How to calculate the maximum ratio of V/f to run it? Am I looking at Ld or Lq value for this? Let's say these are the characteristics - haven't ch...
Problem Description I am trying to design a BLDC inverter and I am in doubt of what would be the right approach for estimating the input capacitor size/type. Doing it empirically or throwing every...
This question is related to my previous question. I want to drive a brushed DC motor using H-bridge. To power the motor two 18650 cells will be used in series. The issue is that I want to limit th...
I have decided to try design a band-pass filter with a cut-off frequency of 10kHz and bandwidth of 2 Hz. $$ \frac{1}{\sqrt{LC}} = 10001 \rightarrow LC = 1/100020001 sec^{2}$$ $$ \frac{R}{L} = 2...
I was looking for guidelines of how to select appropriate cables for applications (I am interested in DC), I found IEC 183 standard which talks about high voltage cable selection for AC. Also, the ...
Which capacitors have smaller self resonance frequency?I would bet my money on electrolytic capacitors because they are usually much bigger than the ceramic capacitors however I don't know if they...
