Rangkaian Driver Led Dot Matrix 8 X 8

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on a series of below you can find out how to drive an led matrix with 64 LEDs (8 rows by 8 columns - 8x8 display) or less eg 35 LEDs (7 rows by 5 columns - 5X7 dot matrix). Driving a 64 LED matrix display is quite simple and just requires

matrix led drive for more eg 128 or multiplier you can develop its own.

Skema Rangkain Driver Led Dot Matrix 8 X 8

It uses persistence of vision to let you drive the 64 led matrix with only 10 microcontroller outputs! Normally you would need 64 outputs for 64 LEDs but by using multiplexing and a helper chip you can get away with 10.

LED Display multiplexing simply means turning on one led for a short period of time and doing this repeatedly for each LED.

If you do this fast enough then your eye will not notice any flicker.

Note: The unit used in this project is simply an array of 64 LEDs.
The LEDs are no different to any other LEDs but it saves a huge amount of soldering as all the wiring has been done for you.Or you could wire it up yourself if you can't get hold of the module.
If you wire it yourself you still only need 10 control wires (just wire you leds the same as shown in the module diagram).

RANGKAIAN DRIVER (Penggerak) PLAYBACK TV

Driver (Penggerak) PlayBack TV


This is an efficient flyback driver for modern cylindrical rectified television flybacks. Frequency range can be increased using multiposition switch for other values of C3 capacitor, for example 2 nF for 80KHz-200000KHz, but didn't found flybacks with so high resonant frequencies, in addition with higher values of c3 , eg 200nF, 2uF the frequency will drop making possible the use of ignition coils, and rectified power transformers @50Hz to charge high voltage electrolitic caps at 300-400V).

Skema rangkaian driver (penggerak) playback TV

The 555 is wired as an astable and the capacitor is charged only through the 4,7Kohm trimmer (notice the diode) and discharged only through the 2.2 Kohm trimmer, making the duty cycle full adjustable. The square wave is then feed in a totem pole made up of a 2N3904 and a 2N3906, which are cheap, and easy to find. The totem pole ensures the gate being charged and discharged very fast (approx 50nS). The IRF840 is a cheap reliable and powerful power mosfet, it has current capability of 8 A continuous and 32A pulse, 800V drain source voltage, protecting internal zener diode. There is a snubbing network to ensure that voltage spikes are kept low (unless the insulation of the transformer start to leak) protecting both transistors and 555 IC. 100 ohm is a compromise between decay time and voltage spike.


Note:
The flyback driven in this way can supply a significant current, aldough the heart fibrillation starts at 30mA I recommend caution to avoid painful arc-burns. The arc is a hot plasma, never operate the circuit in presence of flammable substances. Charging high voltage capacitors is a serious life threat, so if you arent unexperienced just draw arcs and no more This device when rectified generates static voltage that can be a little annoying

Rangkaian 12VDC Fluorescent Lamp Driver

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Whenever there is a need for battery-powered lighting, like for camping, solar powered cottages, cars, boats, planes, or emergency purposes, fluorescent lamps have a great appeal. Firstly, they are very much more efficient than glow lamps, so they produce much more light for less power consumption. Secondly, their light color stays constant while the battery runs down.

In this article I will offer driver circuit for 12 V/5Watt fluorescent lamp, this circuit used a normal 220 to 10V stepdown transformer in reverse to step 12V to about 240V to drive a lamp without the need to warm the filaments.

Skema Rangkaian 12VDC Fluorescent Lamp Driver

Note:

• Q1 (IRF510 MOSFET) must be installed on a heat sink
• Dangerous ...!! Please be careful, This series contains 220 VAC that can sting you.

The IC1 TLC 555 is wired as an astable multivibrator for producing the necessary oscillations.The MOSFET Q1 is used to amplify the oscillations produced by the IC1.The out put of MOSFET is connected to the primary of the step up transformer to produce a ~240 V AC for driving the florescent lamp.

List Component:

• C1 100uf /25V Electrolytic Capacitor
• C2,C3 100nf Ceramic Capacitor
• C4 100nf /1KV Ceramic Capacitor
• R1 1K Resistor
• R2 2.7K Resistor
• Q1 IRF510 MOSFET
• U1 TLC555 Timer IC
• T1 300mA, 10V/220v Transformer
• LAMP 5W Fluorescent Lamp
• MISC Board, Wire, Heatsink For Q1

Driver Relay Menggunkan Transistor

type='html'>Basic Transistor relay driver

Bipolar transistor is a component that works based on the presence or absence of flow in the foot triggers the base. In the relay driver applications, the transistor works as a switch that at the time did not accept the current triggers, then the transistor will be in the position of the cut-off and does not conduct current, Ic = 0. And when the base receives the flow triggers, then the transistor will turn into a state of saturation and delivers current. The following is a practical circuit of relay drivers that are reliable for use in microcontroller projects.

Skema Rangkaian Driver Relay
Menggunkan Transistor

The circuit on the left is a common collector or emitter follower and has the advantage of one less part since a resistor is not needed in series with the transistor base. However the voltage across the relay coil will be two diode drops less than the supply voltage, or about 11 volts for a 12.5 volt input.

The common emitter configuration on the right offers the advantage of the full supply voltage across the load for most of the delay time, which makes the relay pull-in and drop-out voltages less of a concern but requires an extra resistor in series with transistor base. The common emitter (circuit on the right) is the better circuit since the series base resistor can be selected to obtain the desired delay time whereas the capacitor must be selected for the common collector (or an additional resistor used in parallel with the capacitor).

The time delay for the common emitter will be approximately 3 time constants or 3*R*C. The capacitor/resistor values can be worked out from the relay coil current and transistor gain. For example a 120 ohm relay coil will draw 100 mA at 12 volts and assumming a transistor gain of 30, the base current will be 100/30 = 3 mA. The voltage across the resistor will be the supply voltage minus two diode drops or 12-1.4 = 10.6. The resistor value will be the voltage/current = 10.6/0.003 = 3533 or about 3.6K. The capacitor value for a 15 second delay will be 15/3R = 1327 uF. We can use a standard 1000 uF capacitor and increase the resistor proportionally to get 15 seconds.

Source: bowdenshobbycircuits.info