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12 views

Injecting bits to a parallel communication bus possible?

Antennas can recieve data (bits) because RF signals induce an analog signal into it in a serial format, essentially a voltage that varies over time. My question is can we have an antenna that can ...
0 votes
1 answer
68 views

Why does this transistor amplifier fail if Rc is greater than 50 ohms?

This simple circuit amplifies a 1 µV 50 ohm 7 MHz signal (e.g. RF off an antenna) quite nicely (31 dB): However, I'm stumped as to why R2 must be so low (50 ohms), giving a Ic of close to 50 mA. ...
0 votes
1 answer
26 views

Is the x-capacitor essential in the circuit below?

hi I hear a buzzing noise from c1 and L1 in this circuit C1 used a film capacitor, not an X capacitor (Film capacitors were used instead of x capacitors because of internal space problems.) I thought ...
0 votes
1 answer
5 views

Can a voltage higher than LED maximum be used when using constant-current LED driver?

I am planning to use these components: TLC59283 CREE J Series 5630 LEDs Specifically, I want to create a setup like Figure 9-1 on pg. 22 of the TLC59283 datasheet. Currently, I am trying to choose a ...
0 votes
0 answers
8 views

Analog pulse width detection

I have to make an analog circuit that the input is a pwm, when the pulse width is 1000ms the output must be 0 and when the pulse width is 750ms the output must be 1, i tried using an 555 with a ...
0 votes
2 answers
141 views

Battery powered circuit protection

I’m just curious what kind of protection you would typically expect to see on a battery powered circuit. Circuit in question is a simple 24v dc relay controlled motor. Main power source would be 2x ...
0 votes
1 answer
57 views

Are these filters suitable for this application?

I want to use the ADF4350 as a local oscillator and I want it to sweep as fast as possible from a start frequency A to the end frequency B the issue is the span is large and for that i have to use a ...
0 votes
2 answers
55 views

How can I record with this old fashioned mono microphone? [closed]

I have this microphone that comes with a 3.5mm mono jack connector. When I plug it in to my laptop or my phone it won't work, and I believe the "mono" part is the problem. What do I need to ...
1 vote
0 answers
37 views

Why does my PMSM motor stop unexpectedly?

I have two PMSM motors, motor1 with 8 pole pairs and motor2 with 17 pole pairs I use a gyroscope to measure speed; I use PID controller1 and PID controller2 set two velocity for motor1 and motor2; I ...
0 votes
1 answer
70 views

Battery pack won't charge because it reads 4.2 V

I salvaged a battery pack from an IP camera and I want to know if it's in good shape to use for other stuff. The packaging indicates a nominal voltage of 3.8 V and a capacity of 5000 mAh. I assume it'...
0 votes
1 answer
140 views

How could i connect a 18650 Lion to be able to supply my embedded device while charging?

I'm designing an embedded device that should be always connected to a solar panel to regularly plot his V-I curve.I will embedd two(2) 18650 Lion battery for the autonomy. So to control and protect ...
0 votes
1 answer
29 views

How can i make this idea work in PCB?

Assume i have a source of energy (voltage source), i want to sense the voltage and current of this source and transfer this analog information to an ADC (arduino nano) thus i have to make the voltage/...
0 votes
0 answers
12 views

Confusion with two types of differential coupling

I'm having difficulty to articulate the question. But perhaps I might get close to it by an example. I know that in differential signaling, both the signal and the receiving amplifier can be in ...
1 vote
1 answer
56 views

Why do direct conversion receivers amplify only after mixing?

The vast majority of the simple direct conversion receivers I've seen amplify only after mixing. The RF is filtered before mixing, but not amplified at all. For example (from Solid State Design for ...
0 votes
1 answer
723 views

Startup circuit in flyback power supply

I'm looking into this reference design: https://www.ti.com/lit/pdf/tidrlf7 When U1 turns on the pin 5 outputs a 32 kHz PWM signal which is supposed to turn Q4 on and subsequently turn Q3 off during ...
1 vote
0 answers
13 views

Visualizing 2 Layer PCB Return Currents

Hobbyist moving a manhattan-style prototype of an analog FM radio to a PCB for ease of assembly and access to SMT parts. I have attempted a 2 layer FR4 board with a 1.6mm thickness, as I feel that ...
3 votes
2 answers
2k views

How to determine the load requirement for a 24 VDC power supply

I work in the automotive industry. I got a project to add extra hardware to a particular line. The current hardware requires 24 V, 70 W. We have a power supply unit "Power One HE-24V-7.2A" ...
-1 votes
0 answers
18 views

I need help in 68HC705 programming

I want to burn some 68HC705C8 chips. I am grateful for any help or information.
0 votes
0 answers
17 views

Using latches to capture 8086 bus

Following with that great answer https://stackoverflow.com/questions/78168288/reverse-engineer-lcd-protocol-used-in-mpc2000xl/78377225#78377225 The Latches are LS374 I'm trying to capture the data ...
1 vote
5 answers
110 views

Infinite output impedance in amplifier, instead of 0?

The question asks: "Exercise 14.5 Assume an ideal op amp and use the summing-point constraint to find an expression for the output current io in the circuit of Figure 14.14. Also find the input ...
0 votes
1 answer
283 views

LIS3MDL sensor Vehicle Detection range

I want to use LIS3MDL magnetoresistive sensor for Parking Vehicle Detection project. I compared this with HMC5883L. LIS3MDL 's Full Scale range is +16 Gauss but HMC5883L 8 Gauss. But I did not ...
3 votes
3 answers
208 views
+100

I need help to identify the negative feedback loop in a hysteresis comparator

Can anyone help me identify where the negative feedback path is? I want to determine the feedback factors for both negative and positive feedback, but it's not clear to me where the negative feedback ...
15 votes
5 answers
3k views

How to join two PCBs with a very small separation?

I want to join two PCB boards with "Headers" type connectors, like this image: But the separation between both PCBs must be 4.8mm, as shown in this other image. But with the connectors ...
0 votes
0 answers
24 views

Trying to identify a vintage (1992) diode

I'd like to identify the vintage diode at position D15: This diode is found on a PCB from a 1992 Mercedes 300D (W124) Convenience Control Unit (it controls the windows, sunroof, etc.). I don't think ...
0 votes
2 answers
67 views

Why does tan (θ) equals -j in impedance of reactive circuits?

I'm having trouble understanding the maths for impedance. Suppose we have a voltage of \$V(t)=V_{0}sin({\omega}t)\$ and we plug this into the capacitor equation \$I(t)=C\frac{dV(t)}{dt}\$. This would ...
0 votes
1 answer
43 views

MOSFET or relay for controlling a PC fan?

I have a 12V DC 0.4A brushless PC fan. For my application, I'm going to drive it at a low speed with 5V DC (I tested and it did spin). I want to control it with a 5V logic signal (simply on and off, ...
0 votes
1 answer
58 views

Please identify these SMD's

Please help me to identify some SMD components. Thank you in advance IC1 IC2 IC3 IC4
0 votes
2 answers
148 views

IV curve arithmetic - reference request

When playing around with electrical concepts in my head, I realized that the IV characteristic of any combination of elements, in series or in parallel, can be computed by simply adding the IV curves ...
2 votes
1 answer
9k views

USB-C Connector wiring 3 wires [closed]

Hello, I am looking for a usb c connector suited for three wires. I can’t find them anywhere. The picture shows the broken connector from a 65w usb c charger. Can anyone tell me where I can get a ...
0 votes
1 answer
150 views

LTC5599: why are these baseband inputs passed through 49.9 ohms and the capacitor + SPI

I'm designing a radar transceiver board using the LTC5599. In the datasheet for the part, there is a schematic that shows the circuit configuration for the evaluation board. Here is an image of the ...
0 votes
0 answers
14 views

Altium don't recognize differential pair net naming

I am trying to make a differential pair in Altium Designer. As I know from the documentation the net label should be <some_label>_P for one and <some_label>_N for another. However not any &...
1 vote
1 answer
52 views

Circuit schema 2 ways WS2812 connect with 1 PCB layout

Hey all I am having a difficut time trying to figure out how to go about the following: I am wanting to just make 1 pcb but I am using WS2812B LEDs and therefore needs to be in the correct direction. ...
0 votes
0 answers
42 views

How can I create a round hole in stiffener in Altium?

I am building a flat flex cable assembly. I have two regions Layer1 which has stiffener, and layer 2/3 with no stiffener. I don't see an option on the toolbar or in the menu to create a circle. I ...
0 votes
1 answer
154 views

Select a decoupling capacitor

I have a simple ESP8266 circuit that detects as pulse when a reed switch is open or closed - nothing fancy. I have anti-bounce code configured and everything typically works as expected. Hopefully ...
2 votes
1 answer
236 views

Is my setup for a 5V motor project faulty?

I'm trying to get a motor (5V nailbrush, no name, no specifications whatsoever) to spin for a set time and pause for a set time using a PIC10F200 microcontroller in conjunction with a 2N2222 NPN ...
0 votes
1 answer
71 views

Determining the zeros and poles of a common emitter amplifier

I want to determine the transfer function of the base common emitter amplifier. I don't want to neglect the impedances of the capacitors in the calculations because I want to determine the zeros and ...
1 vote
0 answers
16 views

Why does my W65C51's echomode have weird bit delay?

I've recently bought a new Western Design Company 6551 IC, but after hooking it up I get a weird bit-delay while using the Echomode. When I send a character, for example 'U', it should send (startbit)...
0 votes
1 answer
2k views

Multiple infrared proximity sensors and Arduino

I am wondering if it's possible to connect multiple infrared proximity sensors as this one to an Arduino Uno. I would need to connect 5 of them pointing in different directions. Should I use an ...
0 votes
3 answers
122 views

How do you call wire pins that can be used as jumpers with your breadboard?

I can't seem to find these things on electronics distributor websites. There are a bunch of various pins and connectors, but I can't find these among them. What are they called? I tried "Dupont 2....
2 votes
1 answer
668 views

Reset ATECC508A to default?

Is there a way to reset the ATECC508A from Microchip Technology to default? The configuration zone was already locked.
2 votes
1 answer
2k views

I need help with Eagle CAD how do you edit silk screen how to add copper to the empty spaces

Like the title describes, these are two things I need to know how to do in eagle. Any pointers? P.S. if anyone knows a tricky way to get an image into the silk screen, it would be amazing.
0 votes
3 answers
68 views

Does anyone know what the symbol or footprint is supposed to look like for this toggle switch?

I'm trying to make a circuit diagram on Eagle and I can't find the symbol or footprint for this particular toggle switch called 5646MAB (first pic). I would custom make it myself on Eagle but I have ...
6 votes
4 answers
302 views

Is it correct to apply KVL through the 2 inputs of an op amp?

The question asks; "P14.25 Analyze each of the ideal-op-amp circuits shown in Figure P14.25 to find expressions for 𝑖𝑜. The top part is the question, the bottom is the solution from the ...
-3 votes
1 answer
134 views

How do you make an LED fan sign? [closed]

I was wondering how to make an LED fan sign that consists of 256 white LEDs. Forward voltage is: 3.0-3.2 V and maximum current is 20 mA. Not sure what voltage to use, so I'm open to any suggestions on ...
7 votes
4 answers
5k views

How do you measure nanovolt order signals?

If you have a black box that gives you a nanovolt signal in the output, how would you collect and process it? Signal-to-noise ratio is very low. How do you filter the noise? Let's say the frequency ...
-5 votes
5 answers
5k views

Counter with 4 JK flip-flops synchronous from 3 to 13!

I have to create a counter with 4 JK flip-flop synchronous. The counter shall count in this order: 3 to 13 and then to 3 to 13 and so on. I have to use Logisim simulator. Ok. So I think it's solved. I ...
-3 votes
0 answers
40 views

Confusion regarding working procedure of AI robots? [closed]

Traditionally, robots were programmed using fixed and rule based approach like if-else programming in microcontroller boards like Arduino, and they can work even without internet. But what actually ...
-2 votes
1 answer
167 views

Can you tell me what is this component

I found this electronic component in the road, but I can't tell what it's tend to be because I'm not an electronics guy, can you please tell me what is it ?
0 votes
1 answer
148 views

Constant character darkness on LCD even in low battery

At this time I have an LCD where I hook up a 1k ohm resistor between contrast and ground. As the battery voltage drops, the text on the screen also fades. I could make a manual switch and switch ...
0 votes
1 answer
142 views

Rf Module Receiver With Pt2272 always gets signal

I am just trying to on and of an led with rf module. I have tried lots of module but my works end up with same result. When I feed my receiver, with led connected to data out, it always powers the ...

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