Simple 4 Channel Video Amplifier using NJM2582

A very simple 4 channel video amplifier electronic circuit project can be designed using NJM2582 ic suitable for video applications with SCART connector . Design of the circuit is very simple and require few external electronic parts .

Circuit diagram :

Simple 4 Channel Video Amplifier Circuit Diagram

Some features of the NJM2582 are : Operating Voltage ±5V, +5V, +11V ; 6input 4output , 2input 1output Video SW , Internal LPF , 6dB Amplifier , Internal 75Ω Driver Circuit , DC output for SCART (FUNCTION SW, BLANKING) .

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LM741 Using Dry Cell Battery Charger Circuit

This is Dry Cell Battery Charger Circuit. That can use charger battery get that about 12 hour. When apply to power supply 9 volt the equipment that fix in the circuit use for size battery AA. If use the size C or D should devalue of Resistor RX down be 68ohm and should not lead battery come to serial while voltage in cell battery lower 1.6V.

The Comparator Circuit with (IC741) control Gate output from Pulse Oscillator at use the integrated circuit CMOS 4011 change Transistor that do infront charger battery until voltage tall 1.6V Comparator Circuit more make LED Flasher warn know for protect Charger battery expire. The next time is if friends have Dry Cell Battery that use be finished already , don’t abandon , try apply new again yes.

Circuit Diagram:

 LM741 Using Dry Cell Battery Charger Circuit Diagram

 

Source: Elecircuit

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3 Input Video MUX Cable Driver Using LT1399

The circuit diagram shows a low-cost 3-input video MUX cable driver. In this circuit, the amplifier is loaded by the sum of RF and RG of each disabled amplifier. Resistor values have been chosen to keep the total back termination at 75 Ω while maintaining a gain of 1 at the 75-Ω load. The switching time between any two channels is approximately 32 ns when both enable pins are driven. When designing a circuit board for this cable driver, care should be taken to minimize trace lengths at the inverting input. The ground plane should also be pulled away from RF and RG on both sides of the board to minimize stray capacitance. Current consumption of the cable driver is a modest 8mA.

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Switching Power Supply Using the LMZ14202H

Using the LMZ14202H power switching controller, can be designed a very simple switching power supply circuit that can provide a fixed output voltage covering a wide range of voltages .

Switching Power Supply Circuit diagram

This power switching power supply electronic project will provide a fixed output voltage between 5 and 30 volt from an input voltage between 8 and 42 volt at a maximum output current of 2 ampere . This circuit project power supply require few external electronic parts and can be configured very easy . In the table bellow you can see components value that are required for different output voltage

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SW Receiver Using MK414

A Short Wave Receiver based on the MK484 (formerly ZN414) that includes the tropical bands and 49 metre bands.

SW Receiver Using MK414 Circuit Diagram

Notes:
The original data sheet for the MK414 states a maximum working frequency is around 4 MHz. SW transmissions are so powerful that this receiver will work well with signals up to about 6 or 7 MHz. The 10k resistor controls the operating voltage for the IC which is critical for good performance.

Coil Details:
The tuned circuit consists of a variable capacitor and fixed air spaced coil. For the coil, I wound between 10 and 20 turns of wire on an empty tube of around 1.5 inches diameter. The turns were spaced so that the overall length was around 3 inches. The variable capacitor tuned 0 - 300 pF but there is plenty of scope for experiment here. One final point, you will need an external antenna to receive broadcasts. I have an outside wire that is about 7 meters long and this was quite effective. The antenna can be connected at either end of the coil or via a series capacitor value between 10pF and 100pF.

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LED Torch using NSI45090JDT4G Constant Current Regulator

A very simple LED torch can be designed using the NSI45090JDT4G adjustable constant current regulator (CCR) designed by ON Semiconductor ,using extreme few external components. NSI45090JDT4G device is designed to provide a cost effective solution for regulating current in LEDs. This Constant current regulator is based on patent-pending Self-Biased Transistor (SBT) technology and regulates current over a wide voltage range. It is designed with a negative temperature coefficient to protect LEDs from thermal runaway at extreme voltages and currents.

LED Torch Circuit Diagram

The Radj pin allows Ireg(SS) to be adjusted to higher currents by attaching a resistor between Radj (Pin 3) and the Cathode (Pin 4). The Radj pin can also be left open (No Connect) if no adjustment is required.The maximum current that can be adjusted using this chip is around 160 mA , and the maximum input voltage is around 45 volts The D1 from the circuit shown here is used for reverse battery protection .

Bellow you can see how simple is to design a circuit using this chip ( all data shown bellow are for this schematic ) .
LED’s = ((Vin − QX VF − D1 VF)/LED VF)
Example: Vin = 12 Vdc, QX VF = 3.5 Vdc, D1VF = 0.7 V
LED VF = 2.2 Vdc @ 30 mA
(12 Vdc − 4.2 Vdc)/2.2 Vdc = 3 LEDs in series.

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2 4GHz WiFi ISM Band Scanner Assembly Using the Scanner Part 3

2.4GHz WiFi & ISM Band Scanner. Description and Schematic - Part 1

2.4GHz WiFi & ISM Band Scanner. Firmware and Sowtware - Part 2
 
Assembly

Because the circuit was so simple I took the easy way out and assembled it on a piece of veroboard. Nowadays I would design my own printed circuit board (see custom PCBs).

Rather than finding a connector for the Cypress module I simply soldered single core hookup wire directly to the connector pins. This supported the module and allowed me to position it away from the microcontroller to minimise interference.

The USB cable was made from a standard USB cable with type A and B connectors, I just cut off the B connector and soldered the wires directly to the veroboard with half an inch of heatshrink tubing to keep it neat. That left the type A connector at the other end, ready to plug into the computer.

Note that the red and black wires in the USB cable are +5V and ground respectively. You should check these with a multimeter before soldering them in. The green wire is normally D+ and goes to pin 16 of the 18F2550 while the white is D- and goes to pin 15. The shield does not have to be connected.

The final touch was to drop the assembly into a standard UB5 "jiffy" box with a notch cut out for the USB cable to pass through.

Using the Scanner

With nothing running in the immediate vicinity you will just see background noise, as shown in the screen shot below.

Note that the vertical scale is not calibrated to any particular scale. In fact the scale is just the signal level "factor" reported by the Cypress radio module.

The base level signal represents the noise in the air and in the radio receiver part of the module.

The screenshot below shows a WiFi 802.11n wireless router running on channel 1 and located about 12 metres from the scanner. As you can see the 802.11n (and for that matter 802.11g) routers spread themselves over six channels.

That is the good thing about using channel 1 and 13 for your WiFi setup, you get some unused channels on one side where your spectrum can spread into.

But, using channel 13 has its own problems.

The spectrum on the next screenshot is identical to the one above but this time my microwave oven was heating up dinner. Incidentally, the microwave oven was nothing special, just a domestic model and about 10 metres from the scanner.

As you can see, it totally blotted out the higher frequency end of the band. All microwave ovens seem to use this part of the band and you cannot blame the microwave for their activity, as this was part of the reason for setting up the 2.4GHz ISM band in the first place. Avoiding the microwave oven interference and having some free spectrum on one side is the reason why channel 1 is the best choice for your router (assuming your neighbour has not got there first).

Finally, the screenshot shows a Bluetooth mouse communicating with a computer.

Bluetooth hops all over the 2.4GHz band as it finds the best spots with the minimum of interference. Spikes all over the spectrum is a good indicator of Bluetooth activity. 

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Simple metal detector circuit diagram using CS209A

This simple metal detector circuit diagram is used to sense the presence of metal. A 100uH is used as a sensor. IC C209A has a build in oscillator circuit and the coil L1 form a part of its external LC circuit which determines the frequencies oscillation. When there is a presence of metals, the inductance of the coil is change and the resultant change in oscillation is demodulated to create an alarm. The LED also gives as a visual indicator. This circuit can sense metals up to a distance of few inches. Adjust the value of R1 POT to adjust the sensitivity.

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50 W Power Amplifier Circuit using STK084

This is the circuit diagram of 50W power amplifier circuit which built based on single power amplifier chip of STK084. Its an well-known old IC for audio frequency (AF) amplifier.

This circuit requires dual polarity / split power supply with maximum supply of ± 50. The recommended supply is ± 35 / 2-3A DC current. You may use this split power supply circuit for the amplifier. Use 28V center tap transformer to get about ± 36V output.

Technical Details:

Power output: 50W
RL : 8 Ohm
TDH : 0.2 %
Rin : 52K
Gain : 26.4 dB
Noise : 0.3 mV

Take a note that heatsink is required to be mounted on the power IC since it will going to hot when operated and deliver high power output (high audio volume level). Link

50W Power Amplifier Circuit using STK084,

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5 band graphic equalizer using a single IC chip

The BA3812L is a five-point graphic equalizer that has all the required functions integrated onto one IC. The IC is comprised of the five tone control circuits and input and output buffer amplifiers. The BA3812L features low distortion, low noise, and wide dynamic range, and is an ideal choice for Hi-Fi stereo applica-tions. It also has a wide operating voltage range (3.5V to 16V), which means that it can be adapted for use with most types of stereo equipment.

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