A voltage regulator is an analog circuit that produces a stable output voltage that doesn't vary with input voltage or load changes. Switching regulators are much more efficient than linear ones.

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4answers
191 views

Zener diode voltage too low

I'm trying to regulate 12V to 4.7V with a zener diode. (I'm doing this to protect an AVR's gpio pin, so the current is very low.) I tried the simplest circuit with the zener, but it does not work as ...
0
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0answers
42 views

LM2575 Switch Regulator Shows Poor Load Regulation

I'm working on a project powered by a 12V car battery. The overall circuit is broken down into a number of sub-circuits with varying voltage requirements. The 3 voltages used are: 12V Unregulated ...
-4
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0answers
50 views

D.C power supplies , necessary ratings and characteristics question [on hold]

Can anyone help me with the question please ??? Design giving the necessary ratings and characteristics the necessary for the transformer, bridge rectifier capacitor and regulator , a 12v , 2A ...
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0answers
31 views

Saftly Fast Charge Capacitors from Mains power 100-250v AC with charged cut off

I have an Capacitive Battery Charger but unsure how safe it would be to charge a Capacitor bank with so far one safety concern is if the Capacitive Battery Charger is not charging anything the ...
0
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2answers
47 views

DC Motor control setup and circuit design. 1.5Hp continuous duty @ 95v dc

I have a DC treadmill motor rated at 1.5Hp @ 95v Continuous duty, though the motor label also states that it is a 2.65HP motor and that the amperage is 21.4. I would like to be able to SAFELY run and ...
1
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1answer
73 views

Capacitor in parallel with battery for high current output

I have a long-term application with very low quiescent current and infrequent pulses. I've spec'ed high capacity, low pulse current batteries that will give me the lifetime I need, and I want to ...
1
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2answers
92 views

How to calculate rise time of linear regulator

Given a standard LDO with no soft start, that provides power to a bunch of decoupling capacitors, and a single chip. How do you calculate the rise time of the output rail ahead of time? Is it based ...
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0answers
24 views

regulating voltage acrylic bender

So, I'm starting to build an acrylic bender with 20ga Nichrome wire. I know that the resistance of this product is 1.036 Ohm/ft and I'm planning on using about 3ft. I already have a power supply ...
2
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1answer
29 views

TLV1117 Regulator Thermal Issue

I'm using this Regulator namely TLV1117-50IDCYR for a project that I'm working on. Aparently everything is working fine with this chip but sometimes I feel it's heating too much and I'm not putting ...
0
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0answers
64 views

TS317 voltage regulator 12v to 3v

I'm building a Star Wars Millennium Falcon and happened that I need 12V to my LED strips and I need 3V to each of my single LEDs; And also to my smoke machine that runs at 3V. I went to the Maplin ...
1
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2answers
128 views

Is it OK to use switching regulators to charge mobile phones (and such)?

I had several issues with car usb adapters (dc-dc step-down regulators), and I'd like to make one myself. Issues: Nokia cell phone refusing to charge Motorola phone power supply circuitry fried ...
2
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3answers
61 views

Which way are heat sinks supposed to be mounted?

Which way are heat sinks supposed to be mounted? With the fins around the component, or facing outside?
0
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1answer
29 views

Low Output from MIC5205 LDO Reg

I have a PCB that's designed to output 3.3V from a 5V source. The 5V source I'm currently using sources several amps (3A), though I only need about 100mA. I based the schematic on "Ultra-Low-Noise ...
0
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1answer
55 views

Thyristor voltage regulator with different fireing angle for each period with simulink

First of all I'm really low with EE so please, go easy on me. As home assigment we have to design Thyristor voltage regulator in simulink. It should run for 5 periods with different thyristor fireing ...
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1answer
54 views

MC33063 heating problem

I'm using a MC33063 to generate a -9V supply to power 7 TL084's. I'm using a 7805 regulator to power the 33063 circuit. However, the IC and the regulator heats up a lot -- I burned one IC due to that. ...
0
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1answer
73 views

Take 7.5V from 12V battery

I have two servos which take from 7V to 8V and I want to deliver this voltage from 12V batteries 4200 mAh. I have tried using voltage divider but the result was so bad, I had 2V after applying the ...
0
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1answer
69 views

Calculating feedback resistors for op-amp based voltage regulator

I need to design a voltage regulator with an output range of 20-25V. I managed to re-create this ciruit from a course, but I'm stuck on calculating resistor values. These are the formulas I'm given ...
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0answers
30 views

L7805 ripple rejection

I am building a portable speaker and i want to add a bluetooth reciever(BT to AUX, power from usb). I have 4 li-ion batteries in series for power supply for amplifier. Bluetooth reciever needs 5V ...
0
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1answer
45 views

Basic MOSFET question

I am using a P-Channel MOSFET to build a buck converter and change 12VDC, 2A (from a 12V battery) to 5VDC, 2A (for cell phone charging), should I use a MOSFET rated for 20V, 2A or -20V, -2A? I am new ...
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2answers
69 views

How will the current move?

I hope I've come to the right forum about this... I'm planning on building an e-bike using RC components, except I'm not going to use a transmitter and receiver. Instead, I'll use a Servo Tester to ...
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2answers
136 views

How to regulate 29VAC down to 24VAC?

I have a power supply that says it is 24VAC output, but in reality is is giving a steady 29VAC of output. Is this normal? I am powering sprinkler solenoids that say 24VAC. So my question is how can I ...
0
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2answers
90 views

Microcontroller controlled power supply

Can anyone assist me to make a power supply whose output voltage will be controlled by an Arduino, with the latest voltage setting automatically saved in non volatile memory? I am in an OJT (On the ...
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3answers
114 views

Using a regulator or not?

We have designed a board for mass production . This board has a few components on it, that works with 3v3 , such as MCU, Wi-Fi, and a few more sensors. We used to have a battery, 3.7v to power the ...
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2answers
26 views

minimum regulator for 3.7v battery

i have a 9v solar panel and a 3.7v battery that gives from 2000 to 2500 mA and i want to know the requied specefecations for a regulator to run this solar panel charger
0
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2answers
52 views

Converting “wet” contact closure to “dry” contact closure

I have a "wet" contact closure circuit that is outputting 3V DC. I need to eliminate that voltage to create a "dry" contact closure. How is this accomplished ? Please answer in very basic language, ...
0
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3answers
121 views

Looking for Highly stable 5v Regulator

I want to build a custom battery pack / power supply to run a Raspberry Pi. The board takes 5 volts and I want a 2 amp Max supply. Does anyone know of a circuit that would help me ensure that the ...
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0answers
33 views

433 Mhz + Attiny85 improve range

I want to send information from my Attiny85 to my Raspberry. For the moment. Attiny and Emitter work on 5V Emitter have a 433 Mhz 1/2 waveform antenna I'am using virtual wire Raspberry receiver work ...
3
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2answers
60 views

Combine multiple voltage regulator?

Maybe this is very stupid question but I want to know if I can connect two or more voltage regulator (like LM7L05) to add ampere? Say if 1 is able to source 100 mA then combine 2 to draw 200 mA? Sorry ...
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1answer
69 views

Can a voltage regulator or stabilizer increase voltage and current simultaneously when used with a generator?

I have just built a generator with a stepper motor I found in a photocopier/printer (24VDC, 0.7A) and a transformer. Without load, the voltage is around 406 VAC. With a bulb (230 VAC, 18 W), the ...
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1answer
85 views

Buck-boost converter dropping source voltage

I have two solar panels connected in series, and I'm using them to charge a phone. Together they provide about 7 V when I connect their leads to a multimeter or a basic circuit (i.e. Resistors/etc.). ...
2
votes
2answers
82 views

Can I use an op-amp in voltage follower configuration as variable voltage power supply?

I see that this works in theory, but I my gut feeling says there is a drawback or caveat of which I'm not aware. Basically what I want to achieve is described best by the circuit diagram below. ...
0
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2answers
89 views

Taking an unstable DC voltage, and stabilizing it

I have a DC motor generator (basically the motor spins, and it powers an LED at the moment), and the output current (mA range) and voltage is very unstable. For an entire circuit to run on the ...
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1answer
50 views

Can I dynamically change STM32 voltage during runtime

I'm using an STM32L151 MCU for a battery powered wireless sensor node. I came across the TPS6274x series switching regulator, who's voltage can be reconfigured at runtime by flipping it's inputs. The ...
0
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1answer
35 views

low dropout regulator output voltage

I want to use the DMOS low-Dropout regulator REG102 3V3, but in the datahseet REG102 of the regulator i found two configuratons. The first configuration is without resistors divider and by connecting ...
0
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3answers
111 views

3v3 Microcontroller controlling a MOSFET that needs 5V

I'm designing a heater controller that has a primary input voltage between 12 and 24V. Everything except the heater runs on 3V3, including microcontroller, LED's, potentiometers and the MOSFET. The ...
0
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3answers
157 views

electrolytic capacitor [closed]

if i changed a 63v 1000uf electrolytic capacitor for a 35v 1000uf what would happen its a main smoothing cap on a power regulator board thats running @ 67v dc 8amp and i want to reduce the voltage ...
1
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1answer
65 views

bypass a low voltage shut off [closed]

Is there a way to disconnect or bypass a low voltage shutdown operation? I have a factory made electronic shooting gallery (toy) that runs on 4 AA batteries. I want to run it to a steady 6VDC supply ...
0
votes
1answer
56 views

Dual Dc regulated voltage circuit design

I'm working on my term project which is designing a dual DC regulated voltage that gives a DC voltage between +or-ve 3 to +or-ve 15. I have completed the testing for positive DC output part, but I ...
1
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1answer
93 views

Different pin assignment for same regulator

I got 2 samples of LP2905CZ (TO-92) voltage regulator. First sample is made by TI and second on by On Semiconductor. Links of the datasheets: On Semiconductor TI Due to ignorance, I just read the ...
2
votes
4answers
312 views

LDO or Switching for 24V Input, 5V Output

I have a 24VDC supply that needs to be regulated down to 5VDC to power an Arduino Mega and a XBee Series 2 module. How would you choose between a Switching Regulator (LM2576T) and a LDO Regulator ...
1
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2answers
71 views

Stepping down 12VDC linear power supply to 9VDC

I have a +/-12VDC power supply that I have built up for testing simple audio circuits. It works just fine for me now but I would like to add a permanent +9VDC leg to it. I have never seen a scenario ...
3
votes
2answers
79 views

Please explain the circuit (current regulator test circuit with Zener diode)

my mind needs refreshing so could someone please help explaining analysis of this circuit. It is used for testing a current regulator (LED driver circuit) ('I' in the image). The regulator current is ...
0
votes
1answer
53 views

Negative voltage across ground points under load

All, I have a circuit with an Exar XRP7659 5v 1.5A regulator and a Torex XC6210B 3.3V LDO Regulator. I am using this circuit to charge USB devices at full current and have noticed that when the ...
0
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2answers
40 views

Can I replace U1 (79L05) -5V 1MA with MC7905CT -5V 1A without problem?

I am assembling a metal detector kit of parts. http://silverdog.co.uk/images/BuildingMinipulseRevD.pdf At the end of stage 1 which involves building is 'a simple linear regulator that provides the ...
0
votes
2answers
58 views

Simple way to charge 5 x AA via USB - any off-the-shelf component for that?

I need to power a gadget I am building with 5 x AA batteries (6V), but I also want to be able to recharge it via USB (5V) while the gadget is on (that is, I want to be able to plug and unplug the USB ...
0
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2answers
55 views

Constand output voltage from batteries / rechargable batteries

I'm trying to make myself a battery pack for my DSLR camera. The original battery of the camera has 7.2 V and 1200 mAh. I've also bought a coupler ( a dummy batterie for external DC input ) which ...
0
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0answers
15 views

Reprogrammable Remote Power Supply Raspberry Pi Monitor and Control

I currently have a reprogrammable power supply (HCS-3400) hooked up to be controlled remotely from an control/monitor app provided by the power supply company, Manson. The supply is connected via USB ...
0
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2answers
58 views

DC to DC step-up boost converter compensation pin, what values to use?

Okay, so I decided on a DC to DC boost converter but am having some difficulty figuring out what values to use for the compensation pin capacitors and resistor. The data-sheet really does not go into ...
0
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1answer
56 views

Use reference voltage as power suppy

I am using MCP3202 which does not have Vref as independent input. The datasheet states that the current consumption is: 550 μA max. active current at 5V Can I ...
0
votes
1answer
100 views

3.7V to 9V DC to DC boost step-up converter design help!

I need serious help choosing an IC for my project. I need a step-up boost converter to power my device from a 1000mAh or 2000mAh lithium ion battery. So far I have measured that my device only draws ...