Showing posts with label led. Show all posts
Showing posts with label led. Show all posts
Friday, December 27, 2013
5 LED VU meter circuit diagram using KA2284
This is a simple circuit diagram of 5-LED audio VU meter using IC KA2284/KA2285. The KA2284, KA2285 are monolithic integrated circuit. It is a logarithmic display driver IC. And it is Bar type display driver using 5-Dot LED. The KA2284/KA2285 has a wide range supply voltage capacity of 3.5V-16V, but we recommend to use about a 12VDC power supply.
Circuit Diagram:
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| Fig: 5-LED Dot/Bar (VU meter) circuit diagram |
Usability of this circuit:
- AC signal Meter or DC Level meter.
- Audio VU(Volume Unit) meter in amplifier or such kind of device.
Here IC AN6884 is also can be used instead of KA2284,KA2285. These all are almost same.
Further reading: DOT vs BAR
Further reading: DOT vs BAR
Tuesday, December 24, 2013
LED Scanner
Here is a simple LED chaser simulating a scanner through the back and forth light effect. It used high bright White LEDs to give the chaser effect. The circuit uses an oscillator to produce fast pulses and a decade counter to drive the LEDs.
IC1 is designed as an astable multivibrator to give continuous positive pulses to the decade counter. Variable resistor VR1, R1 and C1 form the timing components. By adjusting VR1, it is possible to change the speed of the scanning LEDs.
Output pulses from IC1 are fed to the clock input of the decade counter IC2. Resistor R2 keeps the clock input of IC2 low after each positive to negative transitions of input pulses. This is necessary because sometimes the clock input of the decade counter stays positive and does not accept input pulses.
LED Scanner Circuit
All the ten outputs are used in the circuit to drive the LEDs. Diodes D1 through D10 (IN 4148) do the trick of forward and backward chasing effect. Out of the ten diodes, eight diodes form OR gates to direct the outputs of IC2 to LEDs. The remaining two diodes maintain the brightness of the two ungated LEDs. First six outputs of IC2 works in the straight way to give the running effect.
The diode connected to the pin 5 of IC2 is connected to the cathode of the diode from pin 10 (5th LED). This reverses the running sequence in the backward direction. Output 6 drives the 4th LED and the process repeats up to the 2nd LED connected to output pin2.The reset pin 15 and the Clock inhibit pin 13 of IC2 are connected to ground so that IC2 can run freely.
IC1 is designed as an astable multivibrator to give continuous positive pulses to the decade counter. Variable resistor VR1, R1 and C1 form the timing components. By adjusting VR1, it is possible to change the speed of the scanning LEDs.
Output pulses from IC1 are fed to the clock input of the decade counter IC2. Resistor R2 keeps the clock input of IC2 low after each positive to negative transitions of input pulses. This is necessary because sometimes the clock input of the decade counter stays positive and does not accept input pulses.
LED Scanner Circuit
All the ten outputs are used in the circuit to drive the LEDs. Diodes D1 through D10 (IN 4148) do the trick of forward and backward chasing effect. Out of the ten diodes, eight diodes form OR gates to direct the outputs of IC2 to LEDs. The remaining two diodes maintain the brightness of the two ungated LEDs. First six outputs of IC2 works in the straight way to give the running effect.
The diode connected to the pin 5 of IC2 is connected to the cathode of the diode from pin 10 (5th LED). This reverses the running sequence in the backward direction. Output 6 drives the 4th LED and the process repeats up to the 2nd LED connected to output pin2.The reset pin 15 and the Clock inhibit pin 13 of IC2 are connected to ground so that IC2 can run freely.
Wednesday, October 2, 2013
220V AC Powered Blinking LED
I needed a pulsating light for a certain signaling. Voltage was 230V. So I decided to make a simple circuit, consisted of a LED diode, two capacitors, two resistors, a diac and a diode. Activity of the circuit is extraordinarily simple. The capacitor charges by the diode and the resistor. When the voltage on the capacitor achieves 30V the diac "releases" the electrical tension and the capacitor empties thorough the diac, LED blinks. Time base is dependent from the capacitor and the resistor, which is in series with diode 1N4007. Capacitor must be at least for 40V.
Readmore...
Monday, September 30, 2013
Fine Control Super Bright LED Pulser
Four timing controls - 12V supply, Suitable for Halloween or Christmas props
This circuit, designed on request for a Halloween prop, allows fine control of a pulsing Super Bright white LED. The four potentiometers or trimmers will set precisely: on, off, ramp up and ramp down time-delays respectively. Ramp up and ramp down time-delays can be set roughly in the 1 - 15 seconds range, whereas on and off time-delays can range from a few seconds to about one minute. A 12V battery or regulated power supply is required, provided it is reasonably stable. Total current drawing is about 25 - 30mA when the LED reaches maximum brightness.
Parts:
R1,R5,R12,R13___10K 1/4W Resistors
R2,R5___________10K 1/2W Trimmers or Lin. Potentiometers
R3______________47K 1/4W Resistor
R4______________22K 1/4W Resistor
R6_______________1K 1/4W Resistor
R7,R8,R9,R14___100K 1/4W Resistors
R10,R11__________2M2 1/2W Trimmers or Lin. Potentiometers
R15____________220R 1/4W Resistor
C1,C2__________100nF 63V Polyester or ceramic Capacitors
C3,C4___________22µF 25V Electrolytic Capacitors
C5_____________220µF 25V Electrolytic Capacitor
D1,D2________1N4148 75V 150mA Diodes
D3______________LED Super Bright white (e.g. RL5-UV2030)
Q1____________BC337 45V 800mA NPN Transistor
IC1___________LM324 Low Power Quad Op-amp IC
IC2____________4093 Quad 2 input Schmitt NAND Gate IC
Notes:
Readmore...
This circuit, designed on request for a Halloween prop, allows fine control of a pulsing Super Bright white LED. The four potentiometers or trimmers will set precisely: on, off, ramp up and ramp down time-delays respectively. Ramp up and ramp down time-delays can be set roughly in the 1 - 15 seconds range, whereas on and off time-delays can range from a few seconds to about one minute. A 12V battery or regulated power supply is required, provided it is reasonably stable. Total current drawing is about 25 - 30mA when the LED reaches maximum brightness.
Parts:R1,R5,R12,R13___10K 1/4W Resistors
R2,R5___________10K 1/2W Trimmers or Lin. Potentiometers
R3______________47K 1/4W Resistor
R4______________22K 1/4W Resistor
R6_______________1K 1/4W Resistor
R7,R8,R9,R14___100K 1/4W Resistors
R10,R11__________2M2 1/2W Trimmers or Lin. Potentiometers
R15____________220R 1/4W Resistor
C1,C2__________100nF 63V Polyester or ceramic Capacitors
C3,C4___________22µF 25V Electrolytic Capacitors
C5_____________220µF 25V Electrolytic Capacitor
D1,D2________1N4148 75V 150mA Diodes
D3______________LED Super Bright white (e.g. RL5-UV2030)
Q1____________BC337 45V 800mA NPN Transistor
IC1___________LM324 Low Power Quad Op-amp IC
IC2____________4093 Quad 2 input Schmitt NAND Gate IC
Notes:
- Wanting to use two white LEDs, the second device must be wired across the Emitter of the transistor and negative ground with its own limiting resistor wired in series, like R15 and D3 in the circuit diagram.
- If common red, yellow or green LEDs are required, please wire two of them in series, in order to present roughly the same voltage drop of one white or blue LED.
- Please note that the unused sections in both ICs must have their inputs tied to negative ground whereas the outputs must be left open, as shown at the bottom of the diagram.
- All time-delays can be increased by changing the value of C3 and C4 to 47µF 25V or even higher. Please vary the value of these capacitors only, as the values of the resistors wired to the four control pots are rather critical and should not be changed.
Wednesday, September 4, 2013
6 Channel LED Driver Using MCP34845
A very simple 6 channel low cost led driver electronic circuit project can be designed using the MCP34845 LED drivers manufactured by Free scale Semiconductor.The MCP34845 LED drivers operates from 5 to 21 volts and is specially designed for use in back lighting LCD displays from 10" to 17"+ for devices like : PC Notebooks , Net books , Picture Frames , Portable DVD Players , Small Screen Televisions , Industrial Displays , Medical Displays , etc.
6 Channel LED Driver Circuit Diagram
The MCP34845 LED drivers is capable of driving up to 16 LEDs in series in 6 separate strings.PWM dimming is performed by applying a PWM input signal to the PWM pin which modulates the LED channels directly.Main features of this driver circuit project are : input voltage of 5.0 to 21 V , boost output voltage up to 60 V, 2.0 A integrated boost FET , fixed boost frequency - 600 kHz or 1.2 MHz , OTP, OCP, UVLO fault detection , LED short/open protection , programmable LED current between 3.0 mA and 30 mA .
6 Channel LED Driver Circuit Diagram
The MCP34845 LED drivers is capable of driving up to 16 LEDs in series in 6 separate strings.PWM dimming is performed by applying a PWM input signal to the PWM pin which modulates the LED channels directly.Main features of this driver circuit project are : input voltage of 5.0 to 21 V , boost output voltage up to 60 V, 2.0 A integrated boost FET , fixed boost frequency - 600 kHz or 1.2 MHz , OTP, OCP, UVLO fault detection , LED short/open protection , programmable LED current between 3.0 mA and 30 mA .
72 LED Clock
In the circuit below, 60 individual LEDs are used to indicate the minutes of a clock and 12 LEDs indicate hours. The power supply and time base circuitry is the same as described in the 28 LED clock circuit above. The minutes section of the clock is comprised of eight 74HCT164 shift registers cascaded so that a single bit can be recirculated through the 60 stages indicating the appropriate minute of the hour. Only two of the minutes shift registers are shown connected to 16 LEDs. Pin 13 of each register connects to pin 1 of the next for 7 registers. Pin 6 of the 8th register should connect back to pin 1 of the first register using the 47K resistor. Pins 2,9,8, 14 and 7 of all 8 minutes registers (74HC164) should be connected in parallel (pin 8 to pin 8, pin 9 to pin 9, etc.).
The hours section contains two 8 bit shift registers and works the same way as the minutes to display 1 of 12 hours. Pin 9 of all 74HCT164s (hours and minutes) should be connected together. For 50 Hertz operation, the time base section of the circuit can be modified as shown in the lower drawing labeled "50 Hertz LED Clock Time Base". You will need an extra IC (74HC30) to do this since it requires decoding 7 bits of the counter instead of 4. The two dual input NAND gates (1/2 74HC00) that are not used in the 50 Hertz modification should have their inputs connected to ground.
72 LED Clock Circuit Diagram
When power is applied, a single "1" bit is loaded into the first stage of both the minutes and hours registers. To accomplish this, a momentary low reset signal is sent to all the registers (at pin 9) and also a NAND gate to lock out any clock transitions at pin 8 of the minutes registers. At the same time, a high level is applied to the data input lines of both minutes and hours registers at pin 1. A single positive going clock pulse (at pin 8) is generated at the end of the reset signal which loads a high level into the first stage of the minutes register. The rising edge of first stage output at pin 3 advances the hours (at pin 8) and a single bit is also loaded into the hours register.
50 Hertz LED Clock Timebase
Power should remain off for about 3 seconds or more before being re-applied to allow the filter and timing capacitors to discharge. A 1K bleeder resistor is used across the 1000uF filter capacitor to discharge it in about 3 seconds. The timing diagram illustrates the power-on sequence where T1 is the time power is applied and beginning of the reset signal, T2 is the end of the reset signal, T3 is the clock signal to move a high level at pin 1 into the first register, T4 is the end of the data signal. The time delay from T2 to T3 is exaggerated in the drawing and is actually a very short time of just the propagation delay through the inverter and gate.
Two momentary push buttons can be used to set the correct time. The button labeled "M" will increment the minutes slowly and the one labled "H" much faster so that the hours increment slowly. The hours should be set first, followed by minutes.
The hours section contains two 8 bit shift registers and works the same way as the minutes to display 1 of 12 hours. Pin 9 of all 74HCT164s (hours and minutes) should be connected together. For 50 Hertz operation, the time base section of the circuit can be modified as shown in the lower drawing labeled "50 Hertz LED Clock Time Base". You will need an extra IC (74HC30) to do this since it requires decoding 7 bits of the counter instead of 4. The two dual input NAND gates (1/2 74HC00) that are not used in the 50 Hertz modification should have their inputs connected to ground.
72 LED Clock Circuit Diagram
When power is applied, a single "1" bit is loaded into the first stage of both the minutes and hours registers. To accomplish this, a momentary low reset signal is sent to all the registers (at pin 9) and also a NAND gate to lock out any clock transitions at pin 8 of the minutes registers. At the same time, a high level is applied to the data input lines of both minutes and hours registers at pin 1. A single positive going clock pulse (at pin 8) is generated at the end of the reset signal which loads a high level into the first stage of the minutes register. The rising edge of first stage output at pin 3 advances the hours (at pin 8) and a single bit is also loaded into the hours register.
50 Hertz LED Clock Timebase
Two momentary push buttons can be used to set the correct time. The button labeled "M" will increment the minutes slowly and the one labled "H" much faster so that the hours increment slowly. The hours should be set first, followed by minutes.
Monday, September 2, 2013
Infrared Receiver with Status LED
This is the latest version of the Improved Infrared Receiver with Status LED which can control any desktop PC with an ordinary remote control. The project comes along with a small PCB in order to save space. It connects to the serial port as stated in the schematic and uses the freeware Girder (www.girder.nl) software together with Igor’s Plugin (www.cesko.host.sk/girderplugin.htm) to send commands to the PC. The potential uses of this device are countless (control MP3 players, CD and DVD players, radio and TV cards, even move the mouse cursor and shutdown the computer remotely !). Again, note that any ordinary remote control can be used by training Girder to learn its signals !
Project Image
Parts list:
R1 3.3K 1/4W
R2 10K 1/4W
R3 100K 1/4W
R4 10K 1/4W
R5 100K 1/4W
R6 220 1/4W
D1 1N4148
D2 LED 3mm
C1 4.7uF/16V Electrolytic
Q1 BC548
Q2 BC558
IC1 78L05
IC2 TSOP 1736/38/40 (may work with Siemens SFH506xx receivers also)
E1 CR2032 3V battery + PCB base
Misc Three pins to connect the serial cable (optional)
The improvements of this project compared to the ones already published in the internet is that it uses regulated power for the infrared receiver module (TSOP 17xx), has improved sensitivity (worked at a distance of about 10 m), and features a status led which is powered by an external battery source and is driven by two transistors. Upon signal reception, the led blinks to provide a visual feedback to the sender.
Infrared Receiver with Status LED Circuit Daigram
The PCB features narrow tracks (16 mil) so special care should be paid during the construction. The 4.7 uF capacitor is bent towards the board in order to save height if the circuit is to be placed in a small plastic box.
The Girder software for this project was preferred because it is first of all freeware, it is stable and customizable, features a large number of commands and supports user plugins. It is a bit difficult to learn at first, but after a while it deploys a great number of possibilities that other programs (even commercial ones) lack. Nevertheless, with the right corrections (pin changes) this project may be used with other software (WinLIRC, IRAssistant, Miriam, PCRemote) but no such testing has been carried out yet. This is maybe a good point for further search.
ΙR Reciever Pin Numer
Source 7 (RTS)
Ground 5 (GND)
Read 1 (DCD)
Project Image
Parts list:
R1 3.3K 1/4W
R2 10K 1/4W
R3 100K 1/4W
R4 10K 1/4W
R5 100K 1/4W
R6 220 1/4W
D1 1N4148
D2 LED 3mm
C1 4.7uF/16V Electrolytic
Q1 BC548
Q2 BC558
IC1 78L05
IC2 TSOP 1736/38/40 (may work with Siemens SFH506xx receivers also)
E1 CR2032 3V battery + PCB base
Misc Three pins to connect the serial cable (optional)
The improvements of this project compared to the ones already published in the internet is that it uses regulated power for the infrared receiver module (TSOP 17xx), has improved sensitivity (worked at a distance of about 10 m), and features a status led which is powered by an external battery source and is driven by two transistors. Upon signal reception, the led blinks to provide a visual feedback to the sender.
Infrared Receiver with Status LED Circuit Daigram
The PCB features narrow tracks (16 mil) so special care should be paid during the construction. The 4.7 uF capacitor is bent towards the board in order to save height if the circuit is to be placed in a small plastic box.
The Girder software for this project was preferred because it is first of all freeware, it is stable and customizable, features a large number of commands and supports user plugins. It is a bit difficult to learn at first, but after a while it deploys a great number of possibilities that other programs (even commercial ones) lack. Nevertheless, with the right corrections (pin changes) this project may be used with other software (WinLIRC, IRAssistant, Miriam, PCRemote) but no such testing has been carried out yet. This is maybe a good point for further search.
ΙR Reciever Pin Numer
Source 7 (RTS)
Ground 5 (GND)
Read 1 (DCD)
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