Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
I don't want to sound rude, but I think my question is quite specific - the addition of the "I-elements" with the purpose of equalization of the core sizes as presented on the drawing.
The other "things involved", like transformer power and winding calculation, are not what I am asking an...
12v / 5A = 2.4 Ohms and you are connecting 2.2 Ohms load, so you are trying to draw more current than what the supply is capable of delivering.
The strip is rated 2.2 Ohms but at what temperature? Also did you measure the resistance to confirm the value?
That 4.6 Ohm resistor in series is...
I have two E-I MOTs with slightly different sizes of the magnetic cores and I would like to rewind them to a single E-E transformer.
Thus my question is - given the difference in the sizes, would it help if I vertically add the "I"-parts to bring the both cores to the same dimensions -...
Thank you Brian.
The first thing I tested was to see if the PIC is resetting by using another pin held high - the PIC is not resetting. Also the watchdog is disabled.
What I find strange is that increasing the PWM frequency over 500kHz (lowering the PR2 value below 12) removes the issue -...
I am trying to implement a PWM on a PIC18F6585. After setting up the PWM registers I get to control the PWM Period and PWM Duty Cycle successfully.
TRISC.2 = 1 'Configure P1A as input
PR2 = 12 'Set PWM period to 2 uS / 500kHz
Thank you indeed that was the problem. I drew the PCB using the wrong model - 2N2222A instead of MMBT2N2222A - looks like their collector-emitter pins are switched.
Anyway, the TIP122-TIP127 are darlington pair transistors and now the circuit works exactly as in the simulation and drives the...
I am trying to figure it out why the following circuit is not working properly in reality while in theory should work. It is a P-CHANNEL FET driver shifting the gate voltage within the limits of the MOSFET.
The input (R39) is a 5v control signal and in my simulation at R37 it should...
I am working on a large PCB with lots of traces and copper fill as ground plane. My PC has an 8-core AMD at 4GHz, 16GB RAM and fast NVIDIA GPU. In the display options I am using hardware acceleration.
- Every time I move a trace or make a change affecting the plane, the entire...
Thank you, much appreciate your feedback and help!
- lowered the input capacitor value as you suggested.
- missed the fact that the comparator is an open drain - I eliminated the FET switches.
- did not have an appropriate OPAMP model for simulation, thus I used this. The actual OPAMP will...
Pulse Peak Track Hold And Reset circuit
I want to measure the peak value of short pulses (close to Gaussian form and about 0.5 - 1 usec duration) spaced at least 50 - 100 usec from each other.
I came up with the attached circuit where the first amplifier tracks the peak value and the...
Thank you for your help barry but I don't know how to.
Does the potential difference between the supply terminals (18v vs 9v) affect the "stability" of the output with regards to fluctuations in the supply?
I am buffering a -5v reference with an OPAMP and I have a split power supply +9v and -9v, referenced to ground. So I was wondering if in this case it would make any difference if the positive supply (V+) of the OPAMP is connected either to +9v or to GND while the negative supply (V-) is...
I have some 16x2 LCDs and want to modify few of them to 3.3v specifications. The only difference between the 5v and the 3.3v version is the missing U3, C1, C2 and disconnected J1.
So any idea what U3 as indicated on the picture might be?
- - - Updated - - -
Ok, found it - U3 is...
I am just sharing some information with the hope that it could be useful to people having this common problem with the SIM900. After fighting with the random restarting of the SIM900 module for couple of days, finally found the problem and I am posting my solutions to that.
Ok, it is 10v nominal, but with 350ma load (as you said) this could drop bellow 7.5v - that's why asked you to measure the supply voltage under load.
If the supply voltage is 10v, output is 5v and the load is 350ma it should be burning hot after 10-15 sec.
Why is it drawing 350ma in that case...
Looking at your schematic I presume that the power supply to the RTC is 5v and the backup is 3v (not 12 as shown)?
You don't need external load capacitors but you have to make sure that the load capacitance of your crystal is 12.5pF - what is the load of your crystal. Where did you get your...
1. 7805 and 1117 regulators are LDO regulators and the 7805 needs at least 2.2v difference in the voltage, where the 1117 has about 1.5v dropout. Are you sure that your main supply can keep 7,2 (6.5) volts at that load? With other words measure your input voltage under load.
2. Do you have a...