The project shown here is a cheap 60W LED dimmer for 12V LEDs/12V LED strips. The circuit is based on the very popular, versatile, and low-cost 555 timer IC, NE555 IC generates a PWM signal and IRF540 MOSFET works as output driver for the LEDs. In this circuit the 555 IC used in an astable multivibrator configuration to generate the PWM, by controlling the charging and discharging of the timing of capacitor C3, using D2, D3 and PR1. Potentiometer R7 is provided to control the intensity of LED connected to connector CN2, Connector CN1 provided to power the project with 12V DC. D1 is power indicator LED. Large thermal area provided as heatsink to cool down the MOSFET. The circuit can drive a load up to 36W (12V X 3Amps) in normal room temperature, and a load up to 5A requires forced air cooling for MOSFET Q1. D1 power LED, CN1 Power supply input, CN2 LED connections. R7 Potentiometer to control the intensity of LED.
60W LED Dimmer for 12V LEDs using 555 Timer – [Link]
This is a mini DC-DC converter with dual output from single 5V DC supply or USB power source (e.g., +/-18V from 5V/USB). The mini board will fit into small space and perform with high efficiency. Basically, the circuit transfers power from 5V/USB to the output side +/-18V with high isolation, without a direct connection between 5V/USB power and output. The power isolation prevents ground loops and provides high noise immunity between input and output. The project is based on SN6501 chip, which is oscillator/power-driver, is specifically designed for small factor devices. The device drives a low profile, center-tapped transformer primary from 5V/USB power and secondary side provides unregulated dual output which can be further regulated as per requirement (e.g., +/-5V, +/-12V). Project is a very easy and simple tool to test and run industrial, scientific project, PLC and I/O modules which require dual output from single input. D2 power LED, CN1 USB A type connector for USB power input, CN3 No isolated 3.3V and 5V DC output, CN2 unregulated dual 18V Output.
SN6501 Oscillator: When the device supply has reached its nominal value ±10% the oscillator is fully operating. However, variations over supply voltage and operating temperature can vary the switching frequencies between 300 kHz and 620 kHz for VCC = 5 V ±10%
The SN6501 is a transformer driver designed for low-cost, small form-factor, isolated DC-DC converters utilizing the push-pull topology. The device includes an oscillator that feeds a gate-drive circuit. The gate-drive, comprising a frequency divider and a break-before-make (BBM) logic, provides two complementary output signals which alternately turn the two output transistors on and off. The output frequency of the oscillator is divided down by an asynchronous divider that provides two complementary output signals with a 50% duty cycle. A subsequent break-before-make logic inserts a dead-time between the high-pulses of the two signals. The resulting output signals, present the gate-drive signals for the output transistors. As shown in the functional block diagram, before either one of the gates can assume logic high, there must be a short time period during which both signals are low and both transistors are high impedance. This short period, known as break-before-make time, is required to avoid shorting out both ends of the primary.
Note: Other than isolated +/-18V, the circuit also provides 3.3V DC @ 150mA and 5V DC @ 200mA. Both 3.3V and 5V outs are non-isolated.
App note from IXYS about their unique digital inrush controller using Zilog’s 8-bit Z8F3281 MCU.
Digital control allows distinctive solutions to control inrush current in typical AC-DC rectifier with capacitive load by limiting capacitor pre-charge current to a predetermined value at each half sine-wave cycle. Capacitor charge is spread over a number of cycles until capacitor is charged proportion of peak value of AC voltage source. Capacitor is charged according to timedependent pulse train. The pulses are designed in a way to provide substantially equal voltage increment applied to capacitor to keep peak of charging current about the same value at each cycle. Number of cycles depends on capacitor value and charge current. For a given capacitor value which is selected depending on desired ripples amplitude, the charge current is a function of number of pulses and its timing position with respect to rectified sine wave. Detailed algorithm of creating pulse train for Digital Inrush Control is described in the Principles of Operation section.
A GitHub user called Wagiminator has posted details about ATtiny84-TinyCalibrator, which is an OSC Calibrator and High Voltage Fuse Resetter for 8-Pin ATtinys. The ATtiny84 was chosen as the microcontroller for the TinyCalibrator because it has exactly the necessary number of GPIO pins. 8-pin ATtinys usually feature few GPIO pins available, so they are usually operated without an external clock. However, its internal oscillator performs well in most applications, but when it comes to precise timing, its +/-10% accuracy is often insufficient. This problem can be solved, the oscillator can be calibrated, therefore increasing its accuracy to +/-2% or more. You can perform this calibration in various ways, and the TinyCalibrator can do this fully automatically by a push of a button.
For the project hardware, Wagiminator made use of a micro USB connector to supply the TinyCalibrator with 5V. He also integrated an HT7333 voltage regulator to power the oscillator. Then he added a switch which he used to to choose whether the oscillator should be powered for 3.3V or 5V. To give out accurate frequency measurements, he operated the ATtiny84 with an external 12 MHz crystal. Since the current software version only requires about 3.7 kByte, an ATtiny44 can also be used. He chose an ST6624 charge pump IC to generate the 12V for the High Voltage Serial Programmer, which was specially designed for such applications and needs only a few external components. The 12V was controlled by a MOSFET and applied to the RESET pin of the target ATtiny if need be, then he protected the remaining programming lines to the target against a short circuit with resistors. For the user interface, He utilizes three buttons and a 128×64 pixels OLED display.
In order for him to carry out the calibration, he uploaded a program to the target ATtiny using the integrated High Voltage Serial Programmer. Also, the factory oscillator calibration value (OSCCAL) is written to the EEPROM. The software programming on the target ATtiny reads the EEPROM and writes the value to the OSCCAL register. It then applies an oscillating signal with half the clock frequency to pin PB0. He notes that “Since the fuses were previously set so that the target ATtiny runs with a prescaler of 8, a signal with 1/16 of the oscillator frequency is applied to PB0.” The code for the High Voltage Serial Programmer (HVSP) has a spectacular approach. The way it is designed is that for each action, a series of instructions are sent over the data lines to the target ATtiny and the corresponding response is read. The process and the instructions are well described in the data sheet above. For the frequency measurement, the timer/counters of the ATtiny84 carry out the measurement. The oscillator frequency of the target ATtiny can be calculated easily. He connected the PB0 of the target ATtiny, which outputs a signal with 1/16 of its oscillator frequency to the T0 input of the ATtiny84, the Timer0 then counts the pulses at T0 and timer1 stops the measurement after a time of 32 milliseconds.
To operate the device, you carry out the following processes:
You select the desired supply voltage (3.3V or 5V) with the switch.
You connect a 5V power supply to the micro USB port.
Then place the ATtiny13/25/45/85 in the IC socket and press any key. Note: use an SOP adapter for SMD parts.
Finally, select the function you want and follow the instructions on the display.
You can find more information about the project, and how it functions on his GitHub page.
Τecate Group’s TPLC series combines the high power density of an ultracapacitor and the rich energy density of a lithium battery
Tecate Group’s TPLC series is UL recognized and RoHS and REACH compliant. The capacitors are ideally suited for applications requiring increased voltage, higher energy density, and an exceptional cycle life that is not available with standard EDLC technology or lithium-ion batteries alone. For industrial applications where essential machine controllers can be impacted by unplanned interruptions, ride through power is provided to mitigate these effects. The TPLC series provides critical pulse power that is required in gas/water utility meters where long cycle life and low self-discharge are essential for efficient and reliable operation. These capacitors are well-suited for data centers where reliable, economical, and compact energy solutions that address the potential loss of cache memory, RAID systems, and storage servers that can be impacted by unplanned power outages are necessary.
Features
Combines the long life (calendar and cycle) characteristics of the ultracapacitor with the high energy density of the Li-ion battery
Volumetric efficiency in small can size with low resistance: 10°F to 450° F
Broad operating temperature range: -25°C to +70°C
Safety: low self discharge, no thermal runaway, open failure with use of safety vent
In this article/video, I introduced an adjustable 30V-4A linear power supply that provides constant voltage and constant current adjustment. The output noise of the power supply is low and has measured using the power analysis feature of the Siglent SDS2102X Plus oscilloscope. All component packages are through-hole, so you don’t need any special tool for soldering. Let’s get started!
Specifications
Input Voltage (max): 35V [30V, max-tested]
Output Voltage (min): 1.28V
Output Voltage (max-tested): 27.35V [28.9Vin, no load, 25C]
Every electronics enthusiast will have one or more multimeters. But have you ever considered purchasing a bench multimeter instead of a hand-held one? These usually offer many more features and a better display. The Siglent SDM3045X is a 4½-digit bench multimeter with a basic accuracy of 0.02% and many interface options. Here follows our impression after having tested it for a few months.
This is the ‘smallest’ bench multimeter from Siglent, out of a series of three, but apart from a fewer number of digits and a lower basic accuracy, this SDM3045X still offers the same feature set that the more expensive versions also offer. If this amount of accuracy is sufficient for you, then this model will give you the best price/performance ratio.
This is a high accuracy current sensor project build using ACS37002 IC from Allegro, which is a fully integrated Hall-effect current sensor with 0.85mOhms integrated conductor. A fast overcurrent alert output, programmable gain settings and analog linear voltage outputs are key features of this project. The sensor has optimized accuracy for current ranges +/-33A to +/-66 A and the analog voltage output is linear for the current of this range. The operating voltage of the project is 5V DC. The output voltage of this sensor is centered at VCC/2 =2.5V. Output sensitivity depends on the jumper settings, please refer to the table below for sensitivity/Gain configuration. CN2 6-pin header connector provided for power input and outputs. D1 is the power LED. Overcurrent alert is set to a minimum but it can be set as per user requirement by changing resistor divider R4 and R5, more information provided below.
High Accuracy Current Sensor with 400Khz Bandwidth using ACS37002 – [Link]
The project shown here is a cheap 60W LED dimmer for 12V LEDs/12V LED strips. The circuit is based on the very popular, versatile, and low-cost 555 timer IC, NE555 IC generates a PWM signal and IRF540 MOSFET works as output driver for the LEDs. In this circuit the 555 IC used in an astable multivibrator configuration to generate the PWM, by controlling the charging and discharging of the timing of capacitor C3, using D2, D3 and PR1. Potentiometer R7 is provided to control the intensity of LED connected to connector CN2, Connector CN1 provided to power the project with 12V DC. D1 is power indicator LED. Large thermal area provided as heatsink to cool down the MOSFET. The circuit can drive a load up to 36W (12V X 3Amps) in normal room temperature, and a load up to 5A requires forced air cooling for MOSFET Q1. D1 power LED, CN1 Power supply input, CN2 LED connections. R7 Potentiometer to control the intensity of LED.
Note 1: Circuit is built as an LED dimmer but it also can be used as a filament lamp dimmer, heater controller, of course, the load has to be withing voltage and current limit capacity of the circuit.
Note 2: Use Resistor R1, R4, R6 0 Ohms to drive 12 LEDs, if LED doesn’t have current control series resistor, choose R1, R4, R6 value as per LED current control.
Note 3: Project has 2 options for PWM adjust, PR1 Trimmer or R7 Potentiometer, for 16mm R7 potentiometer >>>use jumper J1, J2 and R7, for Trimmer Omit >> J1, J2, and R7
Note 4: It is advisable to use C5 Electrolytic Capacitor 1000uF-16V or 470uF/16V for Higher Load up to 5A
There are many Mini Circular Saws available in the market, and it might be confusing getting one appropriate for you. I recently stumbled upon one of such saws, a 110V/220V Electric Mini Circular Saw. The circular saw is suitable for making straight cuts in wood, wood-like material, aluminum, plastic, and steel that has not undergone heat treatment. However, this saw should not be used to cut materials containing asbestos. This saw is designed for household use and should only be used for such purposes.
The mini circular saw has a portable design, easy to carry, store, and features good portability and easy operation. It features a comfortable rubbery handle, which is very durable, and the rubber handle is easy to hold and operate. The mini circular saw is equipped with three cutting blades, and these 3 blades are for different materials, helping you to meet your different requirements. It is easy to operate thanks to the rear motor separating the saw at the center of gravity to suit your hand when in use. The mini circular saw is equipped with an adjustable cutting depth bar to adjust the depth, the maximum depth is 12mmm. One of the benefits of the mini circular saw is that it is lightweight, well-balanced, and a good alternative to bulkier circular saws to perform precise cuts in tight areas that larger options just can’t accomplish. The mini circular saw features air vents for heat dissipation, which help to keep the saw cool and prolong the life of the saw.
Specifications:
Material – Metal
Color – Black + Red
Vacuum Hose Length – About 1.68m
No-load Speed – 8200rpm
Plug Type – US Plug 110V, EU Plug 220V
Sawing Depth – About 0-12mm
The lightweight electric-powered mini saw utilizes a flat, round blade to cut a variety of materials- generally metal, plastic, wood, and even stone (with a diamond cutting edge). The mini circular saw is ideal for one-handed use. The manufacturer utilizes ergonomic handles with on/off triggers the switch and metal/plastic guards to ensure the saw-operator doesn’t accidentally come in contact with the spinning blade. The circular saw also features height, depth & bevel adjustments for enhanced precision. For wood-cuts, the circular saw blades are designed to produce cross-cuts, rip-cuts, or a combination of the two. The vacuum port of the mini circular saw as an added feature is helpful because it minimizes the mess when working indoors. The noise and vibration levels were calculated in accordance with standard EN 60745. The total vibration values (sum of vectors in three directions) were determined in accordance with standard EN 60745.
Notes:
Please allow 1-3 cm error due to manual measurement.
Everyone has different screens, so item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.
Package List:
1 x Mini Electric Saw
1 x Vacuum Tube
2 x Hex Wrench
1 x Wood Saw Cutting Blade
1 x Marble Blade
1 x High-Speed Steel Cutting Blade
The mini circular saw is available on Banggood for $79.99.
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