Servo Motor System Controller Circuit

This is a design circuit for a Servo System Controller circuit. This circuit is used to control a servo motor remotely. This circuit uses the 555 and requires only six extra components.

This is the figure of the circuit;

[Schematic circuit source: Philips Semiconductors Application Note]

Audio Amplifier Circuit with DC Volume Control

This is a design circuit for audio power amplifier. This circuit uses based on TDA7052B. The TDA7052B and TDA7052BT are 0.5 W and 1 W mono Bridge-Tied Load (BTL) output amplifiers with DC volume control. Not only have been designed for use in TV and monitors, but TDA7052B and TDA7052BT are also suitable for use in battery-fed portable recorders and radios. This is the figure of the circuit;

This devices are integrated with a Missing Current Limiter (MCL). When the difference in current between the output terminal of each amplifier exceeds 100 mA (300 mA typ), the MCL circuit is activated. Headphone application will be allowed on this 100mA level (single-ended).

[Circuit source: NXP Application Note]

Voltage to Pulse Duration Converter Circuit

This is a design circuit for voltage to pulse duration converter. This circuit is control using op amp 741. This is the figure of the circuit;

This circuit is used to convert voltage into pulse duration by combining a timer IC and an OP Amp. This circuit can obtain accuracy up to better than 1%. The output signal is independent of the input voltage and still retain the original frequency.

[Circuit source: Philips Semiconductor Notes]

Salt Tester Circuit

This circuit was designed to detect the approximate percentage of salt contained in a liquid. After careful setting it can be useful to persons needing a quick, rough indication of the salt content in liquid foods for diet purposes etc. This circuit is using LM324 as main components. This is the figure of the circuit;

IC1A op-amp is wired as a DC differential amplifier and its output voltage increases as the DC resistance measured across the probes decreases. In fact, fresh water has a relatively high DC resistance value that will decrease proportionally as an increasing amount of salt is added. IC1B, IC1C and IC1D are wired as comparators and drive D5, D4 and D3 in turn, as the voltage at their inverting inputs increases. Therefore, no LED will be on when the salt content of the liquid under test is very low, yellow LED D5 will illuminate when the salt content is low, green LED D4 will illuminate if the salt content is normal and red LED D3 will illuminate if the salt content is high. D1 and D2 are always on, as their purpose is to provide two reference voltages, thus improving circuit precision. At D2 anode a stable 3.2V supply feeds the non-inverting inputs of the comparators by means of the reference resistor chain R8, R9 and R10. The 1.6V reference voltage available at D1 anode feeds the probes and the set-up trimmer R4. One of these two red LEDs may be used as a pilot light to show when the device is on.

Parts:

R1________________470R 1/4W Resistor

R2,R5______________10K 1/4W Resistors

R3,R6_____________220K 1/4W Resistors

R4__________________5K 1/2W Trimmer Cermet

R7________________680R 1/4W Resistor

R8__________________2K2 1/4W Resistor

R9,R10,R11,R12,R13__1K 1/4W Resistors

C1________________100µF 25V Electrolytic Capacitor

D1,D2,D3______3 or 5mm. Red LEDs

D4____________3 or 5mm. Green LED

D5____________3 or 5mm. Yellow LED

IC1_______________LM324 Low Power Quad Op-amp

P1_________________SPST Pushbutton

Probes_________________ (See Text)

B1___________________9V PP3 Battery

Clip for PP3 Battery

Stereo Audio Coder-Decoder Circuit

This is a design circuit for audio coder and decoder. This audio coder-decoder is suitable for home and portable applications like MD, CD and MP3 players. This circuit uses UDA1380 for main components. This is the figure of the circuit;

The UDA1380 is a stereo audio coder-decoder, available in TSSOP32 (UDA1380TT) and HVQFN32 (UDA1380HN) packages. All functions and features are identical for both package versions. The term ‘UDA1380’ in this document refers to both UDA1380TT and UDA1380HN, unless particularly specified. The front-end of the UDA1380 is equipped with a stereo line input, which has a PGA control, and a mono microphone input with an LNA and a VGA. The digital decimation filter is equipped with an AGC which can be used in case of voice-recording.

The DAC part is equipped with a stereo line output and a headphone driver output. The headphone driver is capable of driving a 16 W load. The headphone driver is also capable of driving a headphone without the need for external DC decoupling capacitors, since the headphone can be connected to a pin VREF (HP) on the chip.

[Circuit schematic diagram source: Phillips Semiconductor Notes]

High Efficiency Filter Circuit 3W Switching Audio Amplifier

This is a design circuit for filter circuit for amplifier. This circuit is a simple design circuit that is based on LM4670. This is the figure of the circuit;

The LM4670 is designed to meet the demands of mobile phones and other portable communication devices. Operating on a single 5V supply, it is capable of driving a 4 speaker load at a continuous average output of 2.3W with less than 1% THD+N. Its flexible power supply requirements allow operation from 2.4V to 5.5V. The LM4670 has high efficiency with speaker loads compared to a typical Class AB amplifier. With a 3.6V supply driving an 8 speaker, the IC's efficiency for a 100mW power level is 77%, reaching 88% at 600mW output power. [Schematic circuit source: National Semiconductor Notes].

Boosted Class D Audio Power Amplifier Circuit

This is a circuit of the power amplifier that is regulate by LM48510. This is a simple basic form circuit. This is the figure of the circuit;

The IC integrates a boost converter with a high efficiency mono, Class D audio power amplifier to provide 1.2W continuous power into an 8Ω speaker when operating on a 3.3V power supply with boost voltage (PV1) of 5.0V. When operating on a 3.3V power supply, the LM48510 is capable of driving a 4Ω speaker load at a continuous average output of 1.7W with less than 1% THD+N. The LM48510 is designed for use in mobile phones and other portable communication devices. The high (76%) efficiency extends battery life when compared to Boosted Class AB amplifiers. The LM48510 features a low-power consumption shutdown mode. Shutdown may be enabled by driving the Shutdown pin to a logic low (GND). The gain of the Class D is externally configurable which allows independent gain control from multiple sources by summing the signals. Output short circuit and Thermal shutdown protection prevent the device from damage during fault conditions. Superior click and pop suppression eliminates audible transients during power-up and shutdown.

2.5W Audio Power Amplifier Circuit

This is a circuit design for power amplifier that it has a low gain amp for the output signal. This circuit is based on LM380 op amp IC. This is the figure of the circuit;

The output is short circuit proof with internal thermal limiting. The package outline is standard dual-in-line. The LM380N uses a copper lead frame. The center three pins on either side comprise a heat sink. This makes the device easy to use in standard PC layouts. Uses include simple phonograph amplifiers, intercoms, line drivers, teaching machine outputs, alarms, ultrasonic drivers, TV sound systems, AM-FM radio, small servo drivers, power converters, etc.