This is the circuit diagram of 5VDC single polarity to 12VDC dual polarity converter based on IC LM2595-12 from National Semiconductor. This circuit will convert 5V DC single voltage (+) become 12V DC dual polarity output (+), GND, (-).
Lab Note: The COBs used in different watches may differ somewhat in their configuration. But by trial-anderror one can always find out the appropriate points corresponding to points A, B, C and D. Figure of a second COB used by EFY Lab is shown alongside. The points A and B (on the COB used by… Read More »
ADC0808/ADC0809 Features: Easy interface to all microprocessors Operates ratiometrically or with 5 VDC or analog span adjusted voltage reference No zero or full-scale adjust required 8-channel multiplexer with address logic 0V to 5V input range with single 5V power supply Outputs meet TTL voltage level specifications Standard hermetic or molded 28-pin DIP package 28-pin molded… Read More »
The ADC0808, ADC0809 data acquisition component is a monolithic CMOS device with an 8-bit analog-to-digital converter, 8-channel multiplexer and microprocessor compatible control logic. The 8-bit A/D converter uses successive approximation as the conversion technique. The converter features a high impedance chopper stabilized comparator, a 256R voltage divider with analog switch tree and a successive approximation… Read More »
Automatic Emergency Light Project. When mains is absent, relay RL2 is in deenergised state, feeding battery supply to inverter section via its N/C contacts and switch S1. The inverter section comprises IC2 (NE555) which is used in stable mode to produce sharp pulses at the rate of 50 Hz for driving the MOSFETs. The output… Read More »
DC Motor Controller Project Kit There are three ways to vary the speed of DC motors: Use a gear-box. Use a series resistor. Measure the current drawn by the motor and then calculate the value of a series resistor needed to drop the voltage applied to the motor. Less voltage means the motor will slow… Read More »
This inverter 12VDC to 240VDC project can be used to power electric razors, stroboscopes and flash tubes, and small fluorescent lamps from a 12 volt car battery. In contrast to the usual feedback oscillator type of inverter, the oscillator of this inverter is separate from the output stage, which allows easy adjustment of the oscillator… Read More »
This circuit was built in the lab using the components shown in Figure 1. The -12V output varied between -11.99V and -11.97V under a load variation between 50 mA and 100 mA and a line variation between 4.5V and 5.5V. The +12V output varied between 11.15V and 11.45V under the same conditions. The +12V output… Read More »
The LH0032 is a FET input, high slew rate amplifier capable of driving up to 100mA current. With wide bandwidth, high slew rate, high input impedance and high current drive capability, LH0032 is an ideal choice for many applications that includes high speed integrator, video amplifier, summing amplifier, high speed D/A converters, etc. LH0032 Features:… Read More »