Wiring Schematic diagram: driver

Showing posts with label driver. Show all posts

Tuesday, November 18, 2014

DC motor driver with H Bridge IC L293D

IC H Bridge DC motor driver L298 has two H-Bridge circuit in it, so it can be used to download the drive two DC motors. H Bridge DC motor driver L298 each can deliver currents up to 2A. However, in use, the H Bridge DC motor driver L298 can be used in parallel, so the ability to deliver the H Bridge DC motor driver L298 flow into 4A. The consequences of the installation of H Bridge L298 DC motor driver with the parallel mode, you need 2 pieces Bridge H L298 DC motor driver to control two DC motors using H bridge DC motor driver L298 in parallel mode.

H Bridge Pin IC L298 DC motor driver which is connected in parallel operation mode:
* OUT1 connected to OUT4.
* OUT2 OUT3 linked.
* IN1 is connected to IN4.
* IN2 connected to IN3.
* ENABLE ENABLE A linked to B.

OUT1/OUT4 and OUT2/OUT3 associated with DC motors to be controlled.

Please note that the output of the L298 does not have a safety diode. Thus, the need to add two diodes - flyback diodes, with appropriate current capability, at any point output.

Friday, September 12, 2014

Simple 4A High Speed Low Side Gate Driver

The UCC27518 and UCC27519 single-channel, high-speed, low-side gate driver device is capable of effectively driving MOSFET and IGBT power switches. Using a design that inherently minimizes shoot-through current, UCC27518 and UCC27519 are capable of sourcing and sinking high, peak-current pulses into capacitive loads offering rail-to-rail drive capability and extremely small propagation delay typically 17 ns.

The UCC27518 and UCC27519 provide 4-A source, 4-A sink (symmetrical drive) peak-drive current capability at VDD = 12 V. The UCC27518 and UCC27519 are designed to operate over a wide VDD range of 4.5 V to 18 V and wide temperature range of -40°C to 140°C. Internal Under Voltage Lockout (UVLO) schemary on VDD pin holds output low outside VDD operating range.

4A High-Speed Low-Side Gate Driver Circuit Diagram

Features

Low-Cost, Gate-Driver Device Offering Superior Replacement of NPN and PNP Discrete Solutions
Pin-to-Pin Compatible With TI’s TPS2828 and the TPS2829
4-A Peak Source and 4-A Peak Sink Symmetrical Drive
Fast Propagation Delays (17-ns typical)
Fast Rise and Fall Times (8-ns and 7-ns typical)
4.5-V to 18-V Single Supply Range
Outputs Held Low During VDD UVLO (ensures glitch free operation at power-up and power-down)
CMOS Input Logic Threshold (function of supply voltage with hysteresis)
Hysteretic Logic Thresholds for High Noise Immunity
EN Pin for Enable Function (allowed to be no connect)
Output Held Low when Input Pins are Floating
Input Pin Absolute Maximum Voltage Levels Not Restricted by VDD Pin Bias Supply Voltage
Operating Temperature Range of -40°C to 140°C
5-Pin DBV Package (SOT-23)

Device Uses

Switch-Mode Power Supplies
DC-to-DC Converters
Companion Gate Driver Devices for Digital Power Controllers
Solar Power, Motor Control, UPS
Gate Driver for Emerging Wide Band-Gap Power Devices (such as GaN)

Monday, September 8, 2014

1W LED Driver Wiring diagram Schematic

At present most of people use LED light systems.Because LEDs can save our electricity on the other hand we can see LEDs have good life time.So that most of factories use LEDs to make light diagram.Today Free Circuit Diagrams 4U is going to give you a simple LED driver schema diagram.This can give a smooth current to your LED this can drive 1W LED.

Note:
# Build this schema on a PCB

Sunday, August 17, 2014

Buck Converter 1 Watt White LED Driver

This is an example of efficiently driving a 1 watt white LED from a 12 volt battery using a buck converter. The LED could simply be connected with a series resistor to get the desired current, but the efficiency would be only 25% since the resistor would drop 9 volts while the LED only requires 3. The buck converter provides about 90% efficiency. The idea is to establish a circulating current through the inductor, diode and load, while the switch replenishes the lost load energy on each cycle. The duty cycle of the switch will be the output voltage divided by the input voltage, or about 3/12 (25%) in this case. Its actually a little greater since there is a small (2.2 ohm) resistor in series with the LED that drops about 0.5 volt, so the total load is about 3.7 volts and the duty cycle is around 31%. The schema could also be used to charge AA batteries from a 12 volt source with adjustment to the duty cycle. The driver section uses a CMOS hex inverter (CD4069) where two of the inverters form an oscillator with 31% duty cycle at about 11.5 Khz, or 66us off time, and 21uS on time for the MOSFET switch. The remaining 4 inverters are used in parallel to provide additional drive current to the gate of the MOSFET. The duty cycle can be adjusted with either the 15K or 20K resistors. The minimum inductor value was worked out from E = L * di/dt and a LED current of 250mA. The minimum value is where the current falls to 0 during the switch off time, or 66uS. The peak inductor current would then be twice the average or 500mA and the inductor will charge from 0 to 500mA in 21uS. So, di/dt is 0.5 /.000021 = 23810 amps per second. The inductor voltage (E) will be 12 minus the load voltage 3.7 or 8.3 volts and the minimum inductor value L will be 8.3 / 23810 = 0.35 mH. The actual value used should be somewhat higher to avoid the current falling to zero and to avoid large peak currents and possible saturation. The example here uses a approximate 2 mH inductor so the change in current is about 100mA and the peak current is lower at about 300mA. The current waveform is shown in the LTspice picture below. Notice the current ramps from about 50mA below the average current to about 50mA above the average or about 100mA total change. The 15 ohm resistor in the LTspice picture represents the LED plus a 2.2 ohm resistor. The MOSFET is represented by the SW (switch) component, and the drive schema by the V3 symbol.

The inductor (pictured below) should be rated for saturation current of more than the peak current, or maybe 300mA in this case. The toroid inductor used is fairly large for the task measuring about 1.5 inches diameter with 20 turns of #18 wire. The core is conductive so it probably should be taped in case the wire insulation fails. The picture shows the naked core for illustration. A smaller core with an air gap could be used to avoid saturation, but would require more wire which would add to the losses due to the wire resistance. Another approach is to use a higher frequency so smaller inductors can be used. But this will add to losses since there would be more switching transitions per unit of time, which adds to the loss. The diode is a VSK330 schottky 3 amp variety for low loss, but most any 1 amp rectifier could be used with somewhat less efficiency. The IRFZ44 MOSFET is also an overkill rated at 50 amps max but very low on-resistance of only 28 milliohms. A much smaller device could be used, but I dont have the numbers. Note the schema has no regulation, so the 12 volt input should be stable. If the battery voltage varies, the duty cycle and LED current should be set using the highest expected supply voltage.

link