The main topics presented
1. Program for designing monostable and stable circuits
The article wants to present a small program for designing monostable and stable circuits with circuit 555.
Its major advantages are the extremely friendly Windows interface, the possibility to adjust the RC elements in the diagram, to change the filling factor or to set the oscillation frequency (for stable).
2. Stereo controller
This type of stereo controller is a mount that can be inserted into an electroacoustic chain to process the input signals and send them to a power amplifier.
The stereo controller shown is equipped with an integrated circuit LM1036 with correction functions performed in direct current. These functions are: volume adjustment, balance, low frequency correction, high frequency correction.
The assembly can be done very easily with a very small number of passive components, and can be supplied from a DC voltage source between 9-16Vdc.
3. Multichannel remote control station
The proposed equipment can be used for a variety of applications, such as: remote control of small models, opening garage or apartment doors, triggering a camera, signaling to the house an attempted theft of a car, performing some measurements of remote physical quantities, etc.
4. AT90S1200 microcontroller
The AT90S1200 microcontroller is a programmable electronic circuit based on a low instruction set architecture in the AVR family of microcontrollers.
For programming this type of microcontroller provides the programmer with a set of 89 instructions that can be executed in one or more machine cycles depending on the complexity of the instruction.
The microcontroller has a Flash memory with a size of 1 Kb which supports around 1000 deletion and rewriting cycles.
In fact, the microchip is also provided with an EEPROM memory of 64b which can also be deleted and rewritten about 100.000 times.
5. 0-10V DC voltage calibrator
Calibration consists of comparing the meter with a standard, for the purpose of grading or adjusting, checking, or calibrating the meter.
The purpose of calibrating the measuring devices is to keep them within the tolerated limits of the metrological characteristics. Calibration is a process by which the performance of a device is compared with a standard of known uncertainty, in order to detect and correct deviations from the specific performance of the device.
The most suitable standard for calibrating voltmeters is a voltage standard generator, variable in steps called voltage calibrator.
6. Transverter for 50MHz
The transceiver shown can be attached to a 28MHz transceiver or a 144MHz transceiver, the difference being the use of quartz suitable for the local oscillator. The receiver side has the input between 50-52MHz and the output 28-30MHz or 144-146MHz, energy consumption being 50mA at 13V.
7. MC3357 (Low Power Narrowband FM IF)
The MC3357 circuit is an intermediate frequency amplifier for frequency modulated voice communications. The capsule includes the following stages: oscillator, mixer, amplitude limiter, discriminator, squelch scan control and mute. Powered by 6V it has a typical consumption of 3mA and an excellent sensitivity of 5uV.
8. Portable charger for NiCd batteries
A simple charger scheme is presented, which can charge, in normal mode, from batteries with a nominal voltage of 1.2V (one NiCd element) to those with a nominal voltage of 14.4V (12 NiCd elements) and with capacities of 100mAg or of 500mAh.