Alternating on off switch electronic project circuit with explanation

A very simple alternating on off switch electronic circuit project can be designed using an 4096 CMOS hex inverter and some common electronic parts.
IC1is a regular Hex-inverter type and is constructed with MOS P-channel and N-channel enhancement mode devices in a single monolithic structure.
First push from this alternating on off switch activates the relay and another push de-activates the relay.

The type for D1 in not critical, even a 1N4148 will work.
Q1 transistor is an 2N4401 type , but can be replaced with some other type like : N100, NTE123A, 2N3904, 2N2222, 2N4013, etc.
For C2, if you find the relay acts not fast enough, you can change it to a lower value or use a ceramic cap of around 0.1μF.
The circuit can be powered from a 9 or 12 volts DC power supply circuit .

Unused input pins must be connected to an appropriate logic level and unused output pins must be left open.
Relay used in this project is an 6 volts relay type . R4 and LED1 are optional and can be removed from the circuit .

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Satellite Dish and Antenna location on one cable

With a very long and difficult to pronounce name, Diplexer Satellite Combiner & Splitter is a marvel of electronics, it is a divider and mix of RF combining satellite antenna + DC + local terrestrial antenna digital (VHF UHF HDTV CATV TV ) on a single cable without interference or other problems. The Diplexer Combiner, as it is called, has two entrances, one to the antenna ANT Local VHF and UHF, another SAT for antenna TV, and I / O output with the two mixed signals.

Satellite Dish Antenna and common in one cable

The name comes from Diplexer Duplex , which means double , equivalent to twice or that replicates the service, which operates in two modes or two systems or a communication system consisting of two points that communicate with each other in both directions , at our case are RF signals that are mixed and then separated . This mixer is the lifeline for small spaces , long distances or where the wiring will not support another cable . You can use the same coaxial cable already installed to pass the RF antenna of the local terrestrial and satellite signal + DC together.

Using diplexers (two crossovers ) the main benefit is to use only one coaxial cable, so a reduction of spending on materials and workmanship . The Diplexer Combiner supports a satellite dish , or an LNBF to Receiver C Band or Ku band. It is capable of supporting systems FTA ( Free to Air) as well as C-band KU band , Digital receiver , Analog Receiver , cable TV operators DirecTV , Sky , Via Embratel , Hi , Vivo , Telefonica , among others .

There are hundreds of manufacturers Diplexer but little difference in the electronic issue between him , is more on the mechanics they differ . Most have an antenna input ( ANT ) which can be VHF - UHF - HDTV - CATV , which has a frequency range of 5 MHz to 850 MHz , since the input to satellite dish ( SAT ) has a frequency range of 950 MHz to 2400 MHz ( varies from manufacturer ) . The maximum DC current passing is 500 mA , the loss of RF signal from the satellite avg 3 dB and the impedance is 75 Ohms .

How to Install Satellite TV Diplexer

The installation and operation of the Diplexer Sat TV is quite simple, you should always use two antennas Diplexer one along to mix the signals of the satellite dish antenna and common, and another near the TV and satellite receiver to separate the RF signals. It supports other components in the antenna, including the keys to high frequency multipoint LNBF and mixers VHF and UHF signal Places antennae system.

It is advisable to protect the Diplexer time, especially rain, although toasted and weatherproof, a small water infiltration can cause damage and losses in the RF signal. When installing crossovers let the satellite receiver off. This system is compatible with all satellite receivers analog and digital KU and C band

See this installation manual for Diplexer one of the manufacturers in PDF

Even the Azbox, Elsys, TP-LINK, Tocomsat, Cromus, Duosat, Naza Box, Hicom, azamerica, Telesystem, IZ receptors: boz, Century Midiabox, Bedinsat, etc.

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AM Receiver based on TDA1572 IC

The circuit is a high performance AM receiver based on the Philips TDA1572 IC. The TDA1572 is an integrated AM receiver circuit that has all the essential circuits such as RF amplifier, mixer, IF amplifier, AGC circuit, the pilot signal strength indicator, audio pre amplifier, etc. controlled oscillator incorporated into it. The internal oscillator frequency can be up to 50 Hz and the IC can accept RF signals up to 500 mV. HF inputs are static protected and separate buffer, voltage controlled oscillator makes it possible to use single coils in the circuit.

Inductor L1 connected between pins 14 and 13 of the IC sets the frequency of the oscillator. Potentiometer R12 is used to vary the voltage on the varicap tuning diode D2. C4 is associated with the internal balance of full-wave detector circuit. Pin 11 is the circuit output if the internal field indicator of strength. The power available on this pin is a function of field strength available and has a good linearity for logarithmic input signals.

The intermediate frequency of this circuit is built around 455 KHz. The band pass filter circuit ago about CF1 and CF2 6kHz select the band around the intermediate frequency. In simple words, IF double-balanced mixer output available on pin is filtered and applied to the input of gain controlled amplifier filter capacitors C16 and C17 are used to reduce the solution time of AGC. The transistor Q2 and associated components form the driver circuit M1 field strength meter. Resistors R9 R5and preset can be used to configure the meter. Capacitor C3 is a bypass capacitor for the audio preamplifier circuit of frequency within the IC. Capacitors C16 and C12 prevent noise (if any) of the power line.

TDA7052 is an audio stage 1W amplifier to drive the speaker. TDA7052 is an integrated bridge amplifier that can deliver an output power of 1W at 8 ohm speaker. Capacitor C18 couples the audio output of the TDA1572 to TDA7052. Potentiometer R10 can be used to control the volume.

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Samsung will introduce the Galaxy Note 4 on 3 September

It is expected that Samsung present its new phone Samsung Galaxy Note 4 officially in September during IFA 2014 event held in Berlin, Germany. Now, the Korean media already have an exact date of this phone Samsung.

According to The Korea Times, Samsung will be announcing the Galaxy Note 4 on September 3, a day before the presentation of the Galaxy Note 3 last year.

Samsung is expected to start sending invitations to the event "soon", including that the company would be a bit rushed to launch its new mobile big Lcd because Apple is finally breaking its tradition of offering only one size cell relatively small as the iPhone 6 to gain entry to the high-end market. It is said that Samsung is trying to get the Galaxy Note sale 4 days before what went on Galaxy Note 3 with this same purpose.

It is expected that the Samsung Galaxy Note 4 has a QHD (2560 × 1440) 5.7 inch Lcd, a Snapdragon 805 / Exynos 5433 processor, 3GB of RAM and a 16 megapixel camera that would include the Sony IMX240 sensor. Additionally, he said that the Samsung Galaxy Note 4 would an ultraviolet sensor and Android KitKat.

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Trick jumper switches on the mobile phone antenna

Trick jumper switches on the mobile phone antenna this will affect the capability dual-band mobile phone into one band only, ie 900 MHz.

This trick is very useful to get around the limitations of funds. If you do not want to lose the ability to dual-band mobile phone into one band only, then the alternative is to make the turn with a new IC PA.

ANTENNA JUMPER DIAGRAM

MMI strives to provide complete and accurate information, but MMI is not responsible for any errors / damage that occurs in the use of information we provide.

 

	Noki GAGE QD	Nokia 90
Nokia 6070

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Quick on board Junction Tester

Short diagram or broken pcb tracks can be easily recognized by means of a Multimeter, but this tool can give wrong results when testing the efficiency of a transistor or diode, unless the device under test is unsoldered and removed from the pcb.







Parts:

R1,R9,R11,R12__100K 1/4W Resistors
R2,R3,R6________10K 1/4W Resistors
R4,R5,R10_______47K 1/4W Resistors
R7_______________1M 1/4W Resistor
R8_______________1M5 1/4W Resistor

C1_____________100nF 63V Polyester Capacitor
C2_______________1µF 63V Polyester or Multilayer Ceramic Capacitor
C3,C4___________10µF 25V Electrolytic Capacitors

D1____________1N4148 75V 150mA Diode

Q1_____________BF245 or 2N3819 General-purpose N-Channel FET

IC1____________LM358 Low Power Dual Op-amp

BZ1____________Piezoelectric sounder (incorporating 3KHz oscillator)

SW1____________SPST Toggle or Slide Switch

Red Probe______Insulated probe, Multimeter-like
Black Probe____The same as above

B1______9V PP3 Battery

Clip for PP3 Battery




A further shortcoming affecting such way of testing is the necessity to keep firmly the probes on the pins of the device under test and at the same time to turn the head continually to read the Multimeter display.
This device allows the user to concentrate on the (often problematic) pcb probes placement, because a short, a broken track, a good or burnt transistor or diode, will be signaled by a beep, as follows:

* A train of short beeps (one per second) indicates an efficient diode or transistor junction
* A train of one-second lasting beeps spaced by a very short silence (in practice an almost continuous beep) indicates a shorted junction or, on the contrary, a good pcb track
* A lack of beeps indicates a broken junction or a broken pcb track

Circuit operation:

Both inputs of IC1A are connected together by two equal value resistors (R4 and R5) and to half the voltage supply obtained by means of the voltage divider R2 and R3. So, the same voltage should be present at both input pins.
In practice, half the voltage supply (i.e. about 4.5V) will be present at the inverting input (pin #2) of IC1A, but the constant voltage generator formed by R6 and D1, feeding the non-inverting input (pin #3) of IC1A by means of the voltage divider R7 and R8, clamps this pin to about 4.1 - 4.3V: this will cause the output of the op-amp to stay low.
If the schema input (R2 to R3 junction) is shorted to negative ground (a condition equivalent to a shorted transistor junction) pin #2 of the op-amp will go to 0V and the voltage at pin #3 will decrease to about 0.3 - 0.35V (caused by the constant voltage generator mentioned above): the op-amp output will go high, activating the piezoelectric sounder.
When a real transistor or diode junction is connected to the input of the schema instead of shorting the input probes directly, the piezo sounder will emit only a short single beep just as the probes will come in contact with a good junction, due to the time delay provided by the discharge of C2 when the voltage at pin #3 is falling from about 4.1V to 0.3V.
To provide a better signaling system, Fet Q1, IC1B and related components were added. This op-amp is wired as a 1Hz square wave generator and Q1 acts as a solid-state switch, going on and off one time per second having the Gate driven by the op-amp output. In this way, the junction of the device under test is connected and disconnected to the voltage sensitive schema built around IC1A one time per second and the result will be a clearly audible train of short beeps signaling the good condition of the junction or track under test.




Testing directions:

NPN Silicon Transistors:
Place the Red probe on the Base and the Black probe on the Emitter: a train of short beeps should be heard. If not, the junction is broken or the transistor is a PNP type.
Always holding the Red probe on the Base, shift the Black probe to the Collector: a train of short beeps should be heard. If not, the junction is broken or the transistor is a PNP type.
Placing the Red probe on the Emitter and the Black probe on the Collector should cause no output from the piezo sounder: the same should occur when reversing the probes. On the contrary, if an almost continuous beep is heard, the transistor is dead.

PNP Silicon Transistors:
Place the Black probe on the Base and the Red probe on the Emitter: a train of short beeps should be heard. If not, the junction is broken or the transistor is a NPN type.
Always holding the Black probe on the Base, shift the Red probe to the Collector: a train of short beeps should be heard. If not, the junction is broken or the transistor is a NPN type.
Placing the Red probe on the Emitter and the Black probe on the Collector should cause no output from the piezo sounder: the same should occur when reversing the probes. On the contrary, if an almost continuous beep is heard, the transistor is dead.

Darlington Transistors:
The procedure is similar to that adopted for common transistor types. The main difference is that when testing the Base - Emitter junction, you will hear the train of short beeps even after reversing the probes. This occurs because a couple of resistors is always present across either junction of the two internal transistors forming a Darlington device.
The second difference is due to the fact that an internal diode connected across Emitter and Collector (Anode to Emitter and Cathode to Collector) is always present in these devices. Therefore, with a NPN device, placing the Red probe on the Emitter and the Black probe on the Collector you will hear the usual train of short beeps, but when the probes are reverted there will be no output from the piezo sounder. On the contrary, if an almost continuous beep is heard, the transistor is dead.
PNP devices of this type are tested reversing the probes, as explained above for common transistors.
Please note that when testing the Base - Emitter junction the beeps will be shorter compared to common transistors. This is caused by the fact that two junctions in series are to be measured when testing Darlingtons.

FETs
The testing procedure is the same as that adopted for NPN silicon transistors (N-Channel FETs) or PNP silicon transistors (P-Channel FETs).
The only difference is shown when checking Source - Drain connections (corresponding to Emitter - Collector): a faint, blurring sound will be heard if the device is good, even reversing the probes.

MosFets
These devices cannot be thoroughly tested with this tool, but a MosFet in good condition should cause no beep to be heard when testing all junctions as explained above for common transistors. But the usual train of beeps will be emitted when checking the Source - Drain connection, placing the Red probe on the Source and the Black probe on the Drain of a N - Channel device, because the presence of an internal diode, as explained above for Darlington transistors.

Germanium Transistors
Use the same testing procedure adopted for silicon transistors. The beeps forming the train will last longer than when testing silicon devices: this is due to the lower junction resistance of germanium devices in respect to silicon types.

Silicon Diodes
Place the Red probe on the Anode and the Black probe on the Cathode: a train of short beeps should be heard.
Reversing the probes no beep will be emitted.

Schottky Barrier Diodes
The same as above, but the beeps should last longer.

Germanium Diodes
The same as for Schottky Barrier Diodes.

SCRs and TRIACs
These devices cannot be tested thoroughly, unless they are shorted: in this case an almost continuous beep will be heard.
But this schema can be useful to distinguish a SCR from a TRIAC.
Placing a probe on the Gate and the other probe on the Cathode or, more properly, the MT1 pin of a TRIAC, the Tester will emit the usual train of beeps, even reversing the probes.
When testing a SCR, the train of beeps will occur when the probes are placed in one way and not when reversed.

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