Hobby Projects - Insulation tester, LED Circuits, Meters.
Showing posts with label Power-Electronics. Show all posts
Showing posts with label Power-Electronics. Show all posts

Wednesday, August 16, 2017

Toy SMPS or an Overkill White LED Driver

Jonathan Westhues site of Intriguing Projects include A Test Instrument for HF/LF RFID and a compiler that starts with a ladder diagram and generates native PIC16 or AVR code.

Toy SMPS or an Overkill White LED Driver

Toy SMPS or an Overkill White LED Driver

I sense the load current and control the duty cycle. The PWM pin on the AVR drives the gate of the FET through a couple of BJTs. Note the absence of any input capacitance; Vin looks terrible but it works. The micro power supply section is isolated with an RC.

delabs Notes

This is a nice way to start, learn uC and Power electronics in one go. It does not matter if it an expensive solution for LED Lighting. It certainly is an excellent Educational Project.
It may also be useful to use Intelligent Systems (uC and Firmware) to monitor and manage LED Arrays and control their brightness and color. Large Arrays can be Interfaced to PC by XBee for Home/Office or Factory Lighting Automation and Energy Consumption Optimization.

Microcontroller Interfacing

uC Real World Interface

uC I/O is Keyboard and LCD when you Build a calculator or a Text/Morse Communicator. When you control a motor it is Drive/Speed and Direction for Motor and Tacho or Opto Counters for Feedback. In both cases you have Input and Output which is Logic or Analog which has to reach the CPU.

Monday, July 11, 2016

Electronic Hobby Projects - Chemelec

This is one of the oldest Electronics DIY Project Sites in the Internet. I now discovered he has a dedicated domain too. Gary from Canada has many useful schematics and even provides kits and parts.

Electronic Hobby Projects - Chemelec

Some projects that may ring bells in your DIY Brain
  • A 10 Watt RMS Amplifier
  • A Solar or Wind Charger/Dump Circuit
  • A Cat or Dog Detector
  • Inverter, 12 volt unit, Mos-Fet design
  • A 25 LED Chaser". (Sequencer)
  • A Metal Detector, for Pin Pointing.
  • Watt Meter", Measures True RMS Watts
  • Pulse Induction Metal Detector
A Mos-Fet Power Inverter

A Mos-Fet Power Inverter

This circuit will provide a very stable "Square Wave" Output Voltage. Output Frequency is Adjustable and Stable. Can be used to deliver a wide range of output voltages by using appropriate turns ratio. Additional MosFets can be paralleled for higher power.

Thursday, March 03, 2016

Switching regulator for 3.3V

Circuits with 3.3 volts: For small currents, a voltage regulator is sufficient. Greater efficiency can be achieved with a step-down switching regulator. This circuit proposal is loaded with good one ampere.



Switching regulator for 3.3V

"The switching regulator used works with an oscillator frequency of 52 kHz, the efficiency is mentioned in the data sheet with 80%. The manufacturer guarantees the accuracy of the output voltage of 3% and lists other advantages as a protection against over-temperature and current limiting on. The switching regulator requires a storage inductor (coil) high quality."

Thursday, October 17, 2013

LM317 based Regulated Power Supply

This is a Regulated Power Supply based on the LM317 IC. It will need a Boost Power Transistor and heatsink for higher currents. It is a versatile building block for stable instrumentation supplies. Consumer Electronic gadgets can use a SMPS chip. In case you wish to use a SMPS for a Precision Instrumentation Block, then take extreme care on Shielding and EMI-RFI.

LM317 based Regulated Power Supply

This is a General Purpose Chip, Series Regulation. It can be varied or trimmed. There is an Internal temperature compensated reference. The minimum trim value is around 1.2. In case you want a Low value voltage like 0.5 with a good current, then use a good negative supply to offset the 1.2 V.

The transformer can be s Split Bobbin with Pri-Sec copper shield foil.  This can be earthed along with the metal enclosure. C4 sends any hi-freq components to earth.  It is better if you do not earth the ground but use such capacitors. A Supply should simulate a a battery with both ends floating wrt Earth. A option to eartth the ground is fine. This also helps the user to configure his own dual supplies.

Q1 and R5 form a Short Circuit OR current fold back OR constant current mechanism. TP1 can be used to vary the output voltage.  Better use something like a Bourns 10T trimpot. An open preset may introduce a noise due to dust and vibration. I don’t remember why i added a zener DZ1, a diode may suffice.

See more at my Power Supplies Section.

Wednesday, April 24, 2013

Experiments with the LM2575

The standard buck regulator circuit delivers a +5V output. This is a rather straightforward circuit and will operate with a wide spread of component values. Optimal values should be selected however to get minimal ripple, minimal noise to the power source, maximum efficiency etc. Note that the quiesent current is about 10 to 14mA.

Experiments with the LM2575

Here is a nice way of using this regulator, this can be used for CMOS opamps as you have a -5V too. That means a portable instrument may find this design useful.

The TI Datasheet Layout Guidelines

LM2575 Switching Regulator
LM2575 - Step-Down Adjustable Voltage Switching Regulator with Output Enable

 The Spirit of Hacking and Fixing, Giving back Life to Old Instruments.

Fluke 8050A LCD display replaced with LED seven-segment

"Recently I was able to cheaply buy a second hand Fluke 8050A made in the early eighties. It is a nice 4.5 desktop digit meter, but a typical problem seems to be that the LCD wears out and goes black. Replacement LCD displays are hard to find, not cheap and probably lead to similar problems in due time."

Wednesday, July 18, 2012

Steve Conner of Scopeboy - Tesla to Inverters

Many projects and schematics related to Audio, Guitar, Amplifiers, synthesizers and Music Circuits. There are even Valve Amp and Computer related ideas.

Steve Conner of Scopeboy - Tesla to Inverters

"I've been building Tesla coils for about 4 years. I was inspired to start when I saw some pictures of Tesla coils making sparks on the internet, and wanted to experience one for myself. After my first attempt, I decided to join the online community of coil builders and try some of the new state-of-the-art ideas that were kicking around."

 Steve Conner of Scopeboy - Tesla to Inverters

Amazing Tesla Coils of Steve Conner

Other Projects
  • An 0-30V, 500mA bench power supply
  • How to make gyrators
  • Boosting a tube amp with a transistor one
  • Grid-tied inverter - 1/2 KW

Friday, May 18, 2012

Measureall Workbench Test Instrument

This was a Student Project of mine, it is a very basic instruments that could do most of the tasks on a test bench.

The cabinet used, was available as a part of a Hi-Fi DIY System, The Range and Mode switches were Modular Stackable Interlocked MultiPole Switches. The rest of the Interface were wirewound pots, jacks, sockets and plugs. The front panel was Engraved Acrylic, the panel was the toughest issue we tackled.

I wanted it to look well engineered, at least on the outside. It was a total analog instrument except for the digital indication of ICL7107. Thanks to 'Intersil Hot Ideas' Applications Book.

The above belong to an instrument Measureall shown below.

MeasureAll Benchtop Instrument

Friday, March 23, 2012

Dual Polarity Power Supply

This supply gives both positive and negative outputs. Appropriate Fuses should be used to protect from fire hazard and overload of transformer.

Dual Polarity Power Supply

The Filter capacitor C1 4700uF has an impedance of Xc = 1 / (2 * 3.14 * f * C) which comes to 0.6 ohms at 50 Hz. The impedance of the load at 2A for 24V is R = V / I that is 12 Ohms which is more than 20 times the impedance of the capacitor at 50 Hz. That means less than 1 / 20 of ripple current will flow thru the load. The Regulator also reduces the ripple a little.

Friday, December 17, 2010

Ni-Cd and Li-ion Battery charger Generic

This is a Generic charger that is made by many brands, the circuit is an approximation of all. Some improvements suggested. Some brands in europe and usa also use this circuit. This works well, but may not be in the best interest of battery life. The cost of the charger needs to be low. So this design or configuration is popular.

Battery Level Indicator 

Ni-Cd and Li-ion Battery charger Generic

The more care you show in the charger's battery charging and discharging; the longer its life. Today i manage my UPS batteries manually, both charge and discharge. The batteries are expensive, there is no better way, that is affordable.

Switching Battery Charger with L296 - del20031

Take batteries seriously - this is the source of transportation, power, solar energy reservoir etc. More so in the Future - start here Battery University.

Mains Voltage Stabilizer Circuits

Mains Voltage Stabilizer Circuits

These circuits were drawn for a person in Africa. See the thread here… stabilizer circuit. They were not tested by me, but are quite close to a practical design.

Stabilizer Step up 230V AC 500VA

This circuit is a design i did, not tested by me as yet. It can Stabilize Mains voltage to around +/- 10% . It can be used for both 110V AC or 220V AC inputs with modifications. The Output is 220V AC. There is an overload, under voltage and over voltage trip circuit. With some tweaks and modifications it might work.

Solid-State Stabilizer Step up 110V AC

This circuit is a design concept, not tested by me and i did it just to explain some ideas. The circuit uses opto-coupler MOC3041 of Motorola and the Triac BTA-16-600 of ST as a solid state switch or relay. It also uses the LM324 quad opamp from National Semiconductor which is low power and single supply. As the MOC3041 switches the Triac at zero crossover there is no inter-winding short of transformer on crossover hopefully, the control circuit is designed in such a way that more than one triac will not be turned on at a time, i would like you to give feedback.

Wednesday, October 20, 2010

Professor Mark Csele - Projects and Hobbies

"I present, below, a collection of projects I have worked-on over the past few years. For over a decade, I had taught both embedded systems (microcontroller technology) and digital signal processing and practice what I preach...."

Professor Mark Csele - Projects and Hobbies

Nixie Thermostat - A heating and cooling thermostat employing technologies spanning fourty years from the unique Nixie tube display, circa 1960's, to a PIC 18F microcontroller, circa 2006.

A High-Powered Power Backup Inverter

A High-Powered Power Backup Inverter - The working prototype of the 2 KVA inverter is complete. Fed from an array of lead-acid cells totalling 600 Ah (at 12 Volts), it easily drives real-world loads such as single-phase motors. The inverter has been tested and found to operate at an efficiency of between 71% and 82% driving a variety of both inductive and resistive loads