This converter uses a low-pass filter instead of the usual tuned circuit so the only tuning required is with the receiver. The dual-gate MOSFET and FET used in the mixer and oscillator aren"t critical. Any crystal having a frequency compatible with the receiver tuning range may be used. For example, with a 3500 kHz crystal, 3500 kHz on the receiver dial corresponds to zero kHz; 3600 to 100 kHz; 3700 to 200 kHz, etc..
This circuit has a flat response from 8Hz to 50 kHz at -3 db on tbe 10-mV range. ..
This circuit uses an NE602 as an inversion mixer. U2 is set to run at about 2.5 to 3.5 kHz. U3 drives a loudspe..
The circuit furnishes an initial charging voltage of 2.5 V per cell at 25°C to rapidly charge a batt..
Using an intersil ICL 7106 A/D converter chip and an LED display module, this gauge uses a Sensym Corp. pressure tra..
The use of a switching transistor (like a 2N2222 or 2N3904) allows use of the CD4511B with a common-anode display. should be chosen to provide about 1 mA to drive Ql and Rr should provide enough current to drive the display...
Two simple circuits permit Nicad charging of a battery based on temperature differences between t..
With the 555 timer connected as a multivibrator and an opto-isolator, ..
When the light beam that falls in the CDS photocell is interrupted, transistor (EN3904) conducts thereby triggering SCR1 (CI06) and activating alarm bell. SI resets the SCR. The alarm bell should be a self-interrupting electromechanical type...
The circuit has been designed to accommodate all those who dedicate many hours of their lives by exploring the endless pages of this site. Despite the fact that it consists of only three components (Most were not little!), Is able to provide an indication of whether it actually released the telephone line after a long connection via modem to the network. This can be particularly useful, since there In many cases, the computer claims that the telephone network connection.....
A line amplifier is always a useful unit to have around, whether it is for matching a line signal or raising..
You can use that circuit to drive a relay of 12 V with a trigering signal of 5V. It uses 2 diodes 1N4002, 1 transistor 2N3904 and two resistors...
It is annoying to realize that you have left your car headlights on only to find that the battery is flat. One possib..
Dc power can also be controlled via fiberoptics. The circuit provides an insulated speed control path for a small dc actuator motor (< Vn hp). Control logic is a self-contained module requiring about 300 mW at 12 V, which can be battery powered. The control module furnishes infrared pulses, at a rate of 160 Hz, with a duty cycle determined by the position of the speed adjust potentiometer. The programmable unijunction multivibrator provides approximately 10 mA pulses to.....
This schematic shows a peak-reading diode voltmeter driven by two stages of amplification. A 100-ILF capacitor provides a fairly large time constant, which results in satisfactory meter damping. The limited differential output voltage coupled with an overdamped meter prevents most needle pinning when you select an incorrect range position, or make other errors. An SPST toggle switch selects additional series resistance. ..
The circuit can be used to give a visible or an audible warning that the headlights are on. It uses a 2N1305 ..
Operational Amplifiers
Computer Systems
Oscilloscopes
Transmitters & Receivers
Sensors & Detectors
ANSI Standards
Low Frequency Amplifiers
Power Amplifiers
Number Systems
Regulated Power Supplies
Analogue Filters
Digital Gates
