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63 Threads found on edaboard.com: Regulated Power Supply Problem
I am brand new to the electronics world. I have set up a home station for working on small scale electronics, i.e. soldering stating, antistatic mat and strap, etc.. I have read some basic electronics books and decided to attempt my first small project, assembling a Dual-Output Adjustable Linear regulated power supply from Jameco. I of (...)
Hi, I?m new to the forum, and looking for some info and help for my project. I?m a guitarist myself and facing the problem as many others do, powering bunch of hungry pedals from one power supply on the pedal board. What I would like to do is regulated power supply (...)
there a way to protect the MOSFETs from saturating using resistors or capacitors? Due you are under development stage, I suppose you are using a DC regulated power supply, with limit current protection, wright ? That´s the standard procedure, and if the case, there is no need to do that you are asking.
What are you utilizing to power the device? A poorly regulated power supply combined with the Brown-Out Reset (BOR) active can cause the device to repeatedly reset, essentially suspending device operation. I would recommend utilizing a 100nF decoupling capacitor as close as possible between the Vdd and Vss pins, use a well (...)
Hi, I am an Electronics engineering student and I am working on robotics project. I am using 150W brushed DC motors with sabertooth motor driver to control them. I am trying to follow line without using line sensors. I am getting feedback from 3000 ppr wheel encoders. So, I calculate error from difference between count of encoders and using PID a
some of my circuit components need dc supply voltage. but some needs ac supply voltage (i.e. vibration sensor). how can i design the power supply circuit to cater all these components need? is it ok with a normal voltage oscillator and amplifier to convert 12V(dc) to 24V(ac). i'm thinking of oscillating the (...)
I design regulated DC power supply with parameters shown above. I designed the whole circuit but I want to see any other solutions. Does anybody know where I can find them ? The main problem connected with designing such power supplies (with wide output voltage range) is with error amplifier which must drive (...)
HELP!!! I NEED A power supply WITH A regulated 12V and 9V OUTPUT.HOW CAN I DO THAT? THANK YOU
Hello! I am looking for a schematic for the power supply Westfalia Technica no. 267880. This is a dual adjustable power supply delivering at each output up to 40 V and up to 5 A, with adjustable current limit. Apparently it was manufactured in Russia (or another country which uses cyrillic letters). The (...)
Hello, I need to power a circuit with 3.3V, this circuit includes a ARM7 MCU, a SDCard and a Siemens TC65 GSM Module. I would like to power this module with a Li-Ion 1200mAh battery, for which I own a Charger. The problem is with the power supply design. The LiIon Batt has a 3.7V nominal, and more than (...)
The power supply can only provide a constant voltage level for the load (regulated), the amount of current drawn from the power supply has to do with the load, as the load resistance gets lower the current increases, the only way to increase the current to a specific load is to increase the voltage. It is (...)
hello everyone, I am designing a regulatead power supply from 1 to 15V with 8A load. I used LM338 for this purpose but it was not giving voltage below 1.2V If I give negative feedback then it cant give sufficient current. I also tried LM3150 but it gives very high noise. any suggestion will be acceptable.. thank you! Regards Shr
Hello! I just registered. I am not specifically electronic trained, but I have some hobbyist notions. I am trying to create an adjustable current regulated power supply. Requirements: Input: 3-4V DC (more specifically, a single LiIon cell, 18650) Output: 3-7V DC @ a maximum of 1.5~2 Amperes. constant current, Adjustable via (...)
Greetings Everyone, I've just completed assembling on a breadboard my first 5v regulated power supply using an LM317 and I would like your opinions if its not too much trouble. It works however the voltage is fluctuating between 4.99v to 5.01v. Is this normal and to be expected? I thought it would be more stable. I've included a (...)
I nee a very precious 3.3V DC power supply. I tried with LM317 but output voltage is not preciously regulated to run a bluetooth module. As the module is highly costly so I can't take the risk. Also, the power supply should be small enough to fix in a 2*2*1 inch box. Need help in this case. I/P: 5V-12V DC (...)
time to post a schematic so we can see the problem. Also a centre tapped winding with a bridge rectifier on the outside wires gives a pretty good result if the total voltage is regulated.
If you are using normal AA batteries go for higher current version batteris eg: LITHIUM or any other. Else use an regulated power supply for test purpose. It might solve your doubt on CURRENT rating issues... GOODLUCK:)
You didn't tell a specification of voltage accuracy. If you can live with the accuracy of a transistor voltage follower (-2 mV/K temperature coefficient) and poor load regulation, you don't need a voltage reference. Dividing a regulated power supply should be sufficient.
hi i m using 89c51 to displaying different type of bulbs, and i need a regulated output, the problem is that i m using switching mode, so how can i get a regulated output
then it is not a 7805 problem. it is the 9v battery. the 9v battery , that we get nowdays are fareastern origin and drains very quickly even for low current loads. substitute a new 9v battery and see. or have a regulated power supply.
I need to design power supply for galvanisation process of metal objects and it has to deliver 15V and up to 25A. Any sugesstion is welcomed. I was thinking of linear regulator with few 2N3773 but if there is some more elegant solution please share it with me. Simce
I guess this is happening during chip power up. When the VCC is ramping up, internal regulator is not enabled. So the VCC will be connected to the bandgap. After that, you want to hot switch the bandgap from VCC to your regulated voltage source. Big "back to back switch" can help you to do the switching. It can eliminate the forward bias in
hi folks there seems to be a problem whenever i work on uart module of my pic16f877a. i hav written a simple code transmitting a single character from pic to my pc using max232. i m using a 9.5 v battery to give the regulated 5v(7805) to both my pic and max232. initiallly the code worked fine but after sometime it simply isn;t working anywa
hi I need a regulated 3.3V DC power from a 9V battery source.Any body have any circuit for that at least any idea.
here are some ideas: If all you need is to increase voltage you can build a voltage multiplier with some diodes and capacitors. I dont remember the exact circuit, but you can find it in any book that describes diodes. Consider building a regulated power supply, eliminates problem of dealing with batteries. Check out (...)
Okay, this IS the elementary electronics board, so bare with me... I just finished 2 variable 1.2-30V/2A regulated DC power supplies (one made with perf board and wire, the other with etched board), and it was much easier (and fun!) than I thought (of course, having a schematic drawn by someone else helped :) Now I want to build a comparable
Hi, Voltage divider will be a problem due to its internal resistance. You can get 5V and 3.3V using zener regulators and for 0.5V , use a forward biased diode. The unregulated DC voltage from the transformer /rectifer combination should be about 3V more than the required output. The transformer current rating should be around 200 to 250 mA, t
Hi, I plan to use either 4 cells of alkaline batteries (4 x 1.5V) or an AC adapter of +9V @ 2.2A as the main power source and step-up, step-down this power source to create few different voltage supplies (+12V, +3.3V and +1.8V). My problem is should I be stepping down the +1.8V from the main power source or stepping (...)
You did not mentioned the power rating or supply voltage. Use a regulated power supply (first test it on bench PSU and see the result).
Many people can´t tell the difference between AM and FM radio. For those people this circuit may sound fine. With this circuit you´ll get: 1- Bad frequency and transient response 2- Lots of distortion (class-B output, low open loop gain) 3- Less power than you are expecting unless you have a regulated power supply. It´s (...)
Sounds like your project have a design FLAW! Sometimes a person has to redesign things to fix the bigger problem, instead of just attaching a capacitor. You need to sit down and consider your WORST case power supply usages for everything in the system, then step back and try to determine how to keep your microcontroller working in the (...)
Hi All I have recently finished LPC2368 based PCB. It is working fine apart from strange fault with JTAG interface. When I try to program LPC2368 flash using ULINK2 it mostly fail (not always). I have already googled to see if someone had same problem but couldn't find suggestion that can sort out my problem. sometimes error message is relat
it is very simple, uou must have a DC power whit 7.5V at list and put it on the pin 1 of the 7805 the pin 2 you put it on GND so the pin 3 you have the regulated 5V supply. you can use one capacitor in the pin 1 to GND and another in the pin 3 to GND, about 100nf is ok. but remember that you need a DC power in the (...)
Hi All! I am trying to make a 0-15 volt regulated power supply with LCD display. I am using AT89S52, ADC0804 and JHD162A LCD Display. I am using Assemby code to program the microcontroller. Every thing is working fine. The ADC is sending the digital data output in binary value which I am converting to Decimal and then to ASCII digits to (...)
Hi, even you replace the fuse it will keep burnt in. Some component was damage and must be replace before you replace the fuse. Check the electrical pathway of dc jack to its power supply. Moreover, check the capacitors, bridge rectifiers and other passive components in the power supply(inside laptop). And then check the (...)
Elliott Sound Products - Linear power supply Design Martin E. Meserve - K7MEM - Un-regulated power supply Design
Hi Ian, I guess you have a regulated power supply and you want to you use a resistor for current sensing and feedback. Then it will dissipate low power. For example, a 0.1 ohm in series produces a voltage drop of 0.3 V for 3A and will dissipate 0.9 W. Right? Or are you thinking in current limitation just by the serier (...)
While the output DC current should not exceed 1.0-1.5 A for 7805 to regulate (and the appropriate heat sink should dissipate the heat), measure the INPUT voltage. It should not exceed ~32 V including any short peaks. Measure the output current; if it exceeds 1.5A, use LM350 3A, 5V regulator, or, connect a 2N3055 power transistor as a current buffer
It's a regulated power supply with a voltage zero crossing detector. The zero point won't be very well defined in this circuit but it will occur once per half cycle. As it stands there is no output waveform, to make it work you will need an additional resitor from the "to mcu" connection to the MCUs supply line (probably the (...)
As the load VOLTAGE is regulated by the 5.1V Zener, you need to indicate load CURRENT. You can do it before the Zener, by making the LED a part of the dropping resistor. If the load current is larger than ~10 mA (most LEDs run at ~10 mA), then connect a shunt in parallel with the LED, to adjust LED current while leaving the Zener at its operation
i am using pickit3 to program pic24fj128gb106 but m facing problem while programming ic.. Firstly, do you have a low ESR cap of 10uF attached between Vddcore/Vcap and Vss pins? Secondly, are all the Vdd/Vss pins appropriately connected? Is the ENVREG pin tied to 3.3v? Thirdly, which pair of PGCx/PGDx are you using
Hi all, In your opinion is it possible to use a constant current source (i.e. LED Driver) as a digital circuit power supply (like attached schematic)? current source specification: Pout=3W, Isc=200 mA, Voc=20v and the desired regulated voltage is 5V, 100mA. Thank in Advance, Reza
I am struck in the design of boost converter. :!: this is a switched capacitor type of boost converter. My input voltage is a single battery supply, 1.2V. With this input voltage I canot design most of my internal blocks like bandgap,comparator, oscillator..etc. The mos is 3.3V mos So, I need to design an internal supply voltage of 3.3V. A
I had a similar problem with a PIC driving a relay. It produced a spike in the Unregulated side of the power supply. That sneaked into the regulated +5 to the pic. I cured it by adding a small series resistor and a couple of capacitors to gnd. (.1uF and 10uF in parallel). To filter the relay (...)
I need to get true zero from the opamp. So I need -5, or maybe even -1 for that purpose. It is best to get -5v to match the +5. power has to be linear regulated . Is there a simple idea out there? can I just stack 2 LDO together and use the middle as ground? thanks Ahgu
This regulator uses a feedback loop. The voltage on the + and - inputs of the opamp stay at the same voltage. The ouput voltage gets divided by the 5K and 1K resistors. IF the divided down voltage from the psu out is lower than the reference voltage the opamp output will swing negative causing the transistors to let more current through so the
Techqs, Are the sensors and associated circuits powered by a regulated supply? If not, this might help. Ragards, Kral
dear friends, i hvae made a simple project with 89c51 and i am in trouble. the project is --> 8 relays, 8 switches. when one wsitch is pressed, one relay becoms on and all others off. so simple. but the problem is --> at the start, when i firstly ON the supply, ( +5v from a regulated supply), all the LEDS blink once (...)
I understand, that the regulated voltages are still correct. If so, the converter is possibly generating strong interferences. You didn't tell about the used RF band, but generally using SMPS with RF could be an issue. At least an appropriate PCB layout and good filtering is required.
hello, i am making an offline SMPS. When i switch on there will be inrush current so i want to limit it. -but not using an NTC as it has no protection when SMPS is repeatedly power cycled. However, the limiting circuitry will otherwise be a lot of components.....relay, relay driver, resistor, power supply for relay etc ...or if i (...)