Reading time: 4 minute The BC107 family, 108, 109 in the TO-18 metal capsule, has been produced worldwide since 1965 by Philips, Siemens, AEG-Telefunken, SESCOSEM, Texas Instruments, Motorola, Fairchild, SGS Thomson and IPRS Baneasa. After 1975, similar and equivalent transistors were manufactured in plastic capsules, at a cost price 20-40% lower.
Reading time: 2 minute A cheap charger for charging batteries with Ni-Cd or NiMH elements is easy to build using the 555 timer and a few transistors. Charging is done quickly, and the electronic scheme ensures the elimination of the unwanted memory effect in NiCd cells.
Reading time: 9 minute Among the main topics presented in this issue, we list: Linear voltage regulators; Low cost charger for NiCd and NiMH elements; Keyboard with conversion from decimal to BCD; Vu-meter with transistors; Switch-detector for minimum load supplied in alternating current; FM transmitter microphone - for the band 88-108 MHz with a single transistor; Using an LED as a photodiode (light detector); 1W audio amplifier with TDA7052.
Reading time: 5 minute Among the main topics presented in this issue, we list: Battery monitors; MC1496 integrated circuit; 2-zone alarm and / or fire alarm control panel; Voltage inverter - 24Vdc / 220Vac, 50 / 60Hz, 350W; Electronic timer with "start" and "stop" commands; Preamplifier - input trainer for frequency meters; Top 209/210 - TOPSwitch Family - Electronic MOS-FET switch with PWM control.
Reading time: 3 minute Among the main topics presented in this issue, we list: Detector for 220Vac / 50hz electrical paths embedded in the wall; Tx and Rx UHF with voice command activation; LM1875 - 20W audio amplifier with low distortion; VT_ series photoresistors; Twilight automatic supplied directly to the 220Vac / 50Hz mains.
Reading time: 4 minute Among the main topics presented, we list: Function generator for PC 0.01Hz… 1MHz; Electronic components for SMT technology; LDO Stabilizers - Low Drop-Out Voltage Regulators; LCD (III) alphanumeric display programming; Switching source 13.8V / 20A; Pony Prog - Programmer PIC16C (F) 84; LCD display with programmable messages.
Reading time: 4 minute Among the main topics presented, we list: Digital oscilloscope - a channel, for PC; Two-channel remote control receiver; Security systems; Timing presence sensor; Programming alphanumeric LCD displays; Reversible memory counter; Software timers made with C51 series microcontrollers.
Reading time: 3 minute The main topics discussed in this issue: Coil construction; CIS transistors type KT - silicon; Metal detectors; Radio-TV troubleshooting; Transforming TV into a monitor;
Reading time: <1 minut The project is based on the LM555 integrated circuit. For this application IC1 works in monostable mode. The mounting input is connected to terminal 2 of the LM555 integrated circuit. Here we have the "touch sensor" designed from a wire, or from a "fork" type route. Basically, when we touch the wire, or the "fork" route, the K1 relay is activated.
Reading time: <1 minut The project has a simple circuit that turns on the light automatically at night. It is based on 2 NPN transistors (BC547) used in Darlington configuration, and a photoresistor. With the help of a potentiometer, the light sensitivity of the LDR photoresistor can be adjusted.
