# All Questions

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### My sister has a hover round scooter (or whatever their called)

The batteries are bad. While trying to figure out how to replace them I have come across these numbers Mu-1slda 12v27ah C/5 12V32Ah C/20 Does the new batteries have to have the exact numbers or ...
14 views

### How to measure or estimate the phase delay between two analog input channels of this board?

There is a 16-bit data acquisition board with +/-10V range which multiplexes analog inputs and buffers the data to the PC. Specifications are given here (DAS6036 is the model in question). Now I need ...
10 views

### Compilation and synthesis work both fine but the wave simulation seems stuck

The following code is an attempt to implement the responses given in this post, a program that takes in its entry a real number coded in 2's complement in a 16 bit std logic vector (the integer part ...
23 views

### How is the impedance of a circuit calculated when non linearity is introduced from a switch

What is the impedance of the following circuit if the switch operates at the same frequency with the input voltage. Since the switch introduces non-linearity to the circuit, how can I calculate the ...
49 views

### Why does one phase of my buildings mains line show a significant amount of voltage (~60V) when it goes down?

The other day one of the phases of our power faulted and the fuse tripped on the power company side. I measured the voltage at 60-65V. Lights were flickering, and some devices kept running (like a ...
27 views

### how can I order motor protectors T150 electrica? [on hold]

I tried so hard to find how can I order this single motor protector from Electrica: T150 but failed to get it on neither fairnel nor on rs-online. as I am repairing my fridge, how do I make sure that ...
56 views

### Read 8 serial ports at the same time with an Attiny

I'm building a MIDI merger, based on a Attiny (either 84 or 85). How to read multiple serial ports at the same time (for example 8 RX input)? I can't find the blog article anymore, but I think I did ...
65 views

### Strange “step” in i2c plot

I have some errors during debugging I2C chip. I took an oscilloscope and found some strange artifacts on the log: Maybe somebody has a suggestion about such questions? 1. What are these strange ...
67 views

### Can I trust in visual inspection to identify LED terminals?

In the figure above, LED A is a regular 5mm LED and the visual identification of its terminals polarity is well known. As you can see, on LED B the anode is identified by the longer leg, but the ...
27 views

### Problems with mbed LPC1768 double precision

I have a motion profile generator which calculates a position 1000/sec. During the decelerating portion of the move, the following calculation is used: ...
38 views

### Looking for gyroscope drift spec in datasheet

The product page of the BMI088 IMU makes the very impressive claim The automotive-proven gyroscope of the BMI088 has an unmatched bias stability of less than 2°/h However, I can't find this claim ...
54 views

### Suppressing sparks when powering motor controller

When I connect a 36V Li-Ion battery source to a cheap eBay DC motor controller, there's a significant spark on the wire, regardless of connected components. Should I: 1) Add capacitors to the input ...
72 views

### Conversion from fixed point to IEEE 754

I am trying to design a simple processor (in VHDL) that takes in its input a real number coded in the fixed point representation in 2's complement (10 bits for the integer part, and 6 for the ...
74 views

### Electric motors high volts low amps vs low volts high amps

I have a little electric motor that im trying to use to spin a turn dial. I tryed useing a 5volt 1.55 amp power supply but it just dont have enought power to spin it. I can hook it up to my portable ...
21 views

### Freestanding bench tester advice for jitter measurement of 50Hz square wave

I am needing advice about which freestanding bench tester to get for jitter measurement of a 50Hz square wave. I prefer a freestanding piece of bench equipment that does not require a sound card or ...
33 views

### How to fully open the mos-fet with a low input power ac current?

Sorry for the ugly drawing. The ac source(piezoelectric material under vibration) generate ac current and then rectified by the bridge rectifier. The rectified current will be stored in the capacitor. ...
82 views

### Electrical engineering [on hold]

Could someone help me in solving this I am having problem in solving it If I want to convert for example from ohms to k What should I do
24 views

### HS-1100WP Servo Question

I am getting HS-1100WP Servo. I want to know if I hook them up directly to 12V and turn off the receiver will it drain my 12V battery? Thanks in advance.
25 views

I am novice in PCB component placement and layout. I have just started my career in Hardware design. We have designed a schematic for Data Acquisition System. In our design, we are using three RF ...
61 views

### What tool do I need for measuring DC power consumption of device over a period of time?

I have a device that's being battery powered and I would like to measure the power consumption over a longer period of time (~24Hours). I want to read both the voltage of my battery and the current ...
36 views

### Understand this surge protector setup

I moved into a flat which has the following electrical setup in the kitchen: Regular looking 4 socket surge protector Combi boiler plugged into surge protector Washing machine plugged into surge ...
47 views

### Given a diode circuit and some of its values, how do I find the temperature?

Let's say I am given the following circuit: along with $$dV_p/dT=0.139mV/K$$: Defining V1 the voltage above Diode D1 and V2 the voltage above diode D2 , we use the expression for the current of a ...
29 views

### what voltages do i need to test on this board for tv not starting [on hold]

can someone tell me why it doesn't say standby on this to test voltages
21 views

### Voltage sweep circuit for non-linear voltage source

I am in a need of a simple circuit for sweeping a voltage of a solar cell and measuring the current. I started with a simple voltage regulator, such as this one: and adjusted it so it would work ...
26 views

### AC to terminal block relays

How can I use one power cable to connect to 4 relays in parallel? So for example, I have one power cable and I want to turn on 3 radiators out for 4. This is my screenshot of the circuit. Terminal ...
593 views

### Lumens specs when buying a flashlight/torch. Why maglite has only 680lm but cheap ones have 900,000?

I am working as a night delivery driver and when its dark and/or rainy it's almost impossible to read many of the house numbers/names I am looking for. I've heard of Maglite and in fact my friend has ...
28 views

### Export contents of block ram to a file in Xilinx FPGA

Assume I have a simple adder Verilog code which does sum=a+b This code is implemented on a Xilinx FPGA (Basys3). At every posedge of clock, I change a and b. I get sum. I run this simulation for ...
32 views

### How to control Radio Clock (DF77) through microcontroller [on hold]

I remove a receiver board from a radio clock that see in below picture. and i connected clock to my test board, I simulated DCF77 with pic18f252 microcontroller, this output complittly same as output ...
52 views

### Circuit with dual power supply

Doing some reverse engineering to a PCB, I drew this part of the circuit. Looking into the datasheets, I found out the comparator (LMC6772) is able to drive the SCR (S6S2) by itself. But the designer ...
22 views

### Can I put two loads on one battery and both loads draw 3.7v as they expect?

I have a project in mind where I replace the tinny 40mAh LiPO battery of a "smart band" (Like a Mi Band 1) and replace it with a regular 18650 LiPo battery, so it last a long time without recharging. ...
23 views

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### How to design a board that gets 12V supply from usb-c? [on hold]

I am trying to create a board similar to the Radxa Rock pi 4 which is open source hardware. The device requires a lot of power so a regular 5V usb-c cable won't cut it, and the component it uses to ...
50 views

### How to draw ~1A from Li batteries without damaging/over-stressing them?

I have designed a micropump driver powered by 2x AA (Li) batteries, the pump is piezoelectric and requires 27V. The pump requires a switching waveform, at the battery side this draws (including ...
46 views

### Different types of full adders

I programmed a full adder in VHDL as shown in the picture below: However, when compiling it, I get the following diagram when I open the Technology Map Viewer: My compilation report also says that I ...
11 views

### Based on Battery capacity finding runtime of motor [duplicate]

How to find 24v 2hp 2500rpm bldc motor run time by using 24v 120ah battery
43 views

### NVG compatibility LED Lights

For an avionics application I need to make a keypanel which has NVG compatible LED lights behind its keys. I am trying to understand how does the NVG compatibility (Night vision Goggles) relates to ...
44 views

### Interfacing LEDs at communication lines for a RS232 to RS485/RS422

I want to use LEDs at the output of R232 to RS485 & RS422 converter to indicate the Rx and TX activities. This converter will be inside an enclosure and I want the RX TX activities to be indicated ...
29 views

### EAGLE SMD Overlap

I have created a footprint for an SMA-Connector like this: The footprint looks like this: There are 3 SMD-Pads on the Bottom Layer and 2 SMD-Pads on the Top. The SMDs on the outside overlap with ...
69 views

### Output capacitors placement in PCB

Having a LDO output that is connected to digital circuitry, I would like to know the best way on how to place the bypass capacitors in this network. Is it better to place higher capacitance ones near ...
104 views

### Why don't smart phones consume power DIRECTLY when plugged in an outlet like a laptop computer? [on hold]

I have learned that laptop computers consume electricity directly from the outlet when it is being used and charge at the same time. So it does not affect the battery life as long as it's plugged to ...
44 views

### Solar power backed circuit to glow 1W LED

What I have achieved so far: Referring https://www.instructables.com/id/BUILD-A-NOCTURNAL-SOLAR-LIGHT-BULB/ , I have successfully built the Solar Garden Light circuit to glow 5mm led using QX5252F. I ...
59 views

### Flat PCB connectors

after finishing my prototype PCB I am now tasked to fit it inside a machine with almost no space. The PCB is not the problem but the Wire-to-board connectors. After intensive search I was very ...
29 views

### How to get right voltage output with Bts7960b H-Bridge?

I am using a NodeMCU to control a BTS7960b motor driver. (datasheet of the BTS7960) This driver controls a 12v dc motor. This image shows my wiring (without the display and the buttons and with a ...
90 views

### How did static charge ruin my control board?

We have a Thermia geothermal heat pump that was working fine up until we had a particularly bad thunderstorm. Lightning took out the power for a while and burned up a DSL modem, a router, and a IP ...
28 views

### Create a nested for loop to sweep two parameters (x,y) to calculate a function E(x,y)

So I would like to plot a 3D space of a function while sweeping two other parameters. I am sure this is not possible to plot in LTspice but is there any way to sweep two parameters while measuring a ...
27 views

### Touch IC TTP223 is hanged at 5V after some times work

I used TTP223 IC which is operated at 5V , i use touch ic output(When High)to turn on the led and (When low) to dim the led. LED is operated by the External 5V and used only touch ic output as signal ,...
33 views

### Pi Filter Calculation

Here is my circuit schematic below. PT4115 feeds LEDs. Load current is 200-215mA and switching frequency is 500kHZ. How do i calculate pi filter or what is the best values for pi filter in this design ...
89 views

### How current can flow through open circuit output and 9v across diode?

,how voltage across diode can be greater than 0.7 volts in forward bias