Tag Archives: Capacitor

High Voltage Capacitor Charger for Photo-Flash Using LT3751

The project is built for professional photo flash systems. Circuit generates high voltage from low voltage battery to operate a photo-flash tube. The project can also be used in other applications like high voltage capacitor charger, emergency strobe, high voltage power supply, security, detonators etc. LT3751 is the heart of the project.

The LT3751 is a high voltage input flyback controller designed to rapidly charge a large capacitor to a user-adjustable high target voltage set by the transformer turns ratio and three external resistors. Optionally, a feedback pin can be used to provide a low noise high voltage regulated output. The LT3751 has an integrated rail-to-rail MOSFET gate driver that allows for efficient operation down to 4.75V.

High Voltage Capacitor Charger for Photo-Flash Using LT3751 – [Link]

A new type of flexible micro-supercapacitors

Researchers from Nanyang Technological University in Singapore build a new type of flexible supercapacitor that aims to be used in wearables and other portable electronics such as T-shirts charging mobile phones. The new type of capacitor is made with out-of-plane wavy structures of graphene micro-ribbons specially placed so that they don’t break when stretched while keeping the electrodes at a relative constant distance.

Graphene normally breaks when stretched but the team of researchers managed to place it in such a way that it can bend without any issue and without affecting it’s electrochemical performance. It’s too early to see this capacitor in commercial devices as it’s capacity is such that can only power an LCD for a minute, but improvement is possible.

source: Elektor

How to Make an Arduino Capacitance Meter

circuitbasics.com has a tutorial on how to measure capacitance using arduino.

With all the different ways capacitors are labeled, figuring out the values of your capacitors can be challenging. Especially if you don’t have a digital multi-meter to test them. In this tutorial, I’ll show you how to build three different capacitance meters using an Arduino and a couple resistors. After finishing this project, you’ll be able to measure all of your capacitors and label them for future reference.

How to Make an Arduino Capacitance Meter – [Link]

Arduino Capacitance Meter Using TM1637

In this instructable by gustavio101 you will know how to make a capacitance meter using Arduino displayed on the TM1637 display with a range from 1 uF to 2000 uF.

To build this project you need the following parts:

    • Resistors
      1x: 220 Ohm
      1x: 10 kOhm, 8000 Ohms also would work depending on your code
    • Capacitors
      You need some capacitors to calibrate your meter, you can use 0 uF, 47 uF, 220 uF and 1000 uF
    • TM1637
      A chip for driving 7-segment displays. Using it in this project is optional, only if you wish to see the results on a small screen. You need also 8 jumper wires to wire the whole circuit including TM1637.
    • Arduino & USB cable

In order to connect the circuit, first you have to connect the 220 Ohm resistor to A0 and pin 11, the 10K Ohm should be connected between the A1 and pin 13, giving the hardware core structure of the meter. The anode of you capacitor should be placed where the A0 and A1 pin are connected, and the cathode to the GND as shown in this picture.

By uploading this code to your Arduino everything will be set! You only need to include the TM1637 library and the code necessary to view your work. Once you open the Arduino IDE open the two files together to have everything done.

#include "TM1637.h"

#define analogPin      0          
#define chargePin      13         
#define dischargePin   11        
#define resistorValue  10000.0F
#define CLK 9
#define DIO 8

TM1637 TM(CLK, DIO);

unsigned long startTime;
unsigned long elapsedTime;
float microFarads;                

void setup()
{
  pinMode(chargePin, OUTPUT);     
  digitalWrite(chargePin, LOW);  
  Serial.begin(19200);
  TM.init();
  TM.set(BRIGHT_TYPICAL);
  delay(1500);             
}

void loop()
{
  digitalWrite(chargePin, HIGH);  
  startTime = millis();
  while(analogRead(analogPin) < 620){       
  }

  elapsedTime= millis() - startTime;
  microFarads = ((float)elapsedTime / resistorValue) * 1000;   
  Serial.print(elapsedTime);       
  Serial.print(" mS    "); 


  if (microFarads >= 1000)
        {
          Serial.print((long)microFarads);       
          Serial.println(" microFarads");
          int value = microFarads;
          int DigitOne = value / 1000;
          int DigitTwo = ((value / 100) % 10);
          int DigitThree = ((value / 10) % 10);
          int DigitFour = value % 10;
          TM.display(0, DigitOne);
          TM.display(1, DigitTwo);
          TM.display(2, DigitThree);
          TM.display(3, DigitFour);
        }
  else
  {    
  if ( microFarads >= 100)
        {
          Serial.print((long)microFarads);       
          Serial.println(" microFarads");
          int value = microFarads;
          int DigitOne = value / 100;
          int DigitTwo = ((value / 10) % 10);
          int DigitThree = value % 10;
          TM.display(1, DigitOne);
          TM.display(2, DigitTwo);
          TM.display(3, DigitThree);
        }
      else
      {
        if (100 > microFarads >= 1)
        {
          Serial.print((long)microFarads);       
          Serial.println(" microFarads");
          int value = microFarads;
          int DigitOne = value / 10;
          int DigitTwo = value % 10;
          TM.display(0, 0);
          TM.display(1, 0);
          TM.display(2, DigitOne);
          TM.display(3, DigitTwo);
        }
          else
          {          
           delay(500); 
          }        
     }
  }
     
  digitalWrite(chargePin, LOW);            
  pinMode(dischargePin, OUTPUT);            
  digitalWrite(dischargePin, LOW);          
  while(analogRead(analogPin) > 0){         
  }


  pinMode(dischargePin, INPUT);            
} 

Check gustavo101’s instructable to know more details and also the project that inspired him to do this one!

Capacitor self-diagnostics

di5525f1

Peter Demchenko discuss about a design idea on how to test capacitors in circuit.

The electrolytic capacitor is far from being the most reliable electronic component. One of its failure modes – a gradual loss of capacity – can hardly be noticed until power supply malfunction occurs. Thus, any chance to monitor the condition of the filter capacitors of an electronic device in situ would be a useful thing.

Capacitor self-diagnostics – [Link]

Analog Capacitor ESR Tester

p1000235-large

TallMan’s lab @ runawaybrainz.blogspot.com build a nice looking and simple analog ESR capacitor meter based on a EEVBlog forum topic.

I finally got round to making my capacitor ESR tester this week after finding a nice simple 5 transistor version by EEVBlog member Jay_Diddy_B. Unfortunately, for me, the design was only SMD so, I decided to replicate his schematic in Eagle PCB using a through hole component design.

Analog Capacitor ESR Tester – [Link]

Circuit lets you test capacitors for leakage

289250-circuit_lets_you_test_capacitors_figure_1

Raju R Baddi @ edn.com has published a circuit that enable you to test electrolytic capacitors and decide if worth using it on a circuit.

The values in the figure are typical for general testing of all capacitors, from 1-nF ceramic versions to 1000-μF electrolytic types. The value of CREF in the circuit is near the value of the test capacitor, CX. You can also choose RREF, by a rotary-switching arrangement, to be greater than or less than 22 MΩ.

Circuit lets you test capacitors for leakage – [Link]

LTC3643 – 2A Bidirectional Power Backup Supply

3643

Linear Technology Corporation introduces the LTC3643, a bidirectional, high voltage boost capacitor charger that automatically converts to a buck regulator for system backup. The proprietary, single-inductor topology with integrated PowerPath™ functionality does the work of two separate switching regulators, reducing size, cost and complexity. The LTC3643 operates in two modes – boost charge mode and buck backup mode. The charging mode efficiently charges an electrolytic capacitor array up to 40V with an internal switch current rating of 2A from an input supply between 3V to 17V. In backup mode, when the input supply falls below the programmable power-fail (PFI) threshold, the step-up charger operates in reverse as a synchronous step-down regulator to power and hold up the system rail from the backup capacitor. During backup, the current limit can be programmed from 2A to 4A, making this device ideal for high energy, relatively short duration backup capacitor systems, power failure backup systems, solid-state drives and battery stack charging applications.

LTC3643 – 2A Bidirectional Power Backup Supply – [Link]

Component Tester FISH 8840 Review

Component_Tester_FISH8840_9494

Alan Parekh @ hackedgadgets.com has a review of a cheap component tested he found on ebay. This device can test bipolar transistors, MOSFET, diodes, thyristors, resistors and capacitors. He writes:

This is an inexpensive component tester called the FISH 8840 which you can find from many online eBay retailers for around $30. The interface is very simple, attach a device to be tested and press the test button. It turns off after about 20 seconds, pressing the off button puts it into sleep mode immediately. There is a ZIF socket that allows you to insert leaded devices and pads that allow you to press SMD devices directly onto the tester.

Component Tester FISH 8840 Review – [Link]

RELATED POSTS

OpenCVMeter – Rediscover Your Capacitors

OpenCVMeter

OpenCVMeter is an open source tool to measure capacitance and leakage current as a function of a capacitor’s working voltage.

When designing circuits, many hobbyists take capacitors for granted – but each type (ceramic multi-layer, aluminum electrolytic, tantalum, mica…) has its own unique properties. Nowadays, ceramic capacitors are the most commonly used capacitors in the industry, but many can lose up to 80% of their rated capacitance near their voltage ratings.

Enter the OpenCVMeter! This meter aims to provide a Capacitance versus Voltage characterization accurate within 1% of the capacitors for your next project (or already have and are starting to wonder about right now…)

OpenCVMeter – Rediscover Your Capacitors – [Link]