TREE

This tiny conductivity tester works with LM 3909. The tester makes a beeping sound if the resistance between the test probes between 0 and 100 O lies. Due to the volume of the beep, the resistance between the test probes can be determined. Audio Lm 3909 IC-conduction tester Circuit Diagram Parts List      R1 = 1 k      C1 = 10 uF      C2 = 100 nF      LS = Loudspeaker 12 to 16 Ω      IC1 = LM 3909

Description . This circuit can be used to test whether mains voltage is present or not without having electric contact with mains line. The CMOS IC CD4033 is the heart of this circuit. The CD4033 consists of a 5 stage decade Johnson counter and an output decoder for converting the Johnson code to a 7 segment decoded output for driving 7 segment LED display . A 10cm long insulated copper wire connected to the clock pin (pin1) of the IC serves as the sensor. The sensor wire has to be placed in the vicinity of the mains wire to be tested. When there is no voltage in the mains line, no voltage will be induced in the sensor wire and the display will show a random digit. When there is voltage in the mains line, a small voltage will be induced in the sensor wire due to electromagnetic induction and this voltage is sufficient enough to clock the CMOS IC CD4033. Now the display will count from zero to nine and repeat. Circuit diagram. Notes. The circuit can be assembled on a Vero board. U...

This circuit is a simple test of USB ports, it is a circuit very useful for anyone working in the field of computer science. To be "stuck" in the PC USB port or an information display Notebook USB device not recognized, just after the yellow LED flashes 3 times, and since it is not a normal USB device, the connection is not established, and micro displays an error message. Tester for USB communication ports Circuit Diagram List of Components 1 Red LED 1 Led Yellow 1 Green LED 3 per 1k 1/8W Resistors 1 USB connector male Simple Test for USB communication ports Indications of LEDs when lit: Red - Polarization USB port was mounted inverted Yellow - Wire USB port data were linked inverted All Deleted - No power to the USB port Green and yellow lights flashing 3 times when turned on - Normal Operation

Suitable for any Infrared emitting device, 3V battery supply. A very simple device allowing a quick check of common Infra-red Remote-Controls can be useful to the electronics amateur, frequently asked to repair or test these ubiquitous devices. A reliable circuit was designed with a handful of components: the LED will flash when any of the Remote-Control push buttons will be pressed. The side of the Remote-Control bearing the IR emitting diode(s) must be directed towards the Photo Transistor (Q1) of the checker circuit: maximum distance should not exceed about 20 - 25cm. . Circuit Diagram:   Infrared Remote Tester Circuit Diagram Parts: R1 = 470K R2 = 47R D1 = LED Any Type Q1 = Photo Transistor Q2 = BC327 B1 = 3V Battery or 2 AA cell Notes: Current drawing of the circuit is less than 1mA when the LED illuminates and 0mA when no signal is picked-up by the Photo Transistor: therefore, SW1 can be omitted. SW1 will be SPST Toggle or Slider Switch Sourced By: Streampowers

This is the simple Remote control tester circuit diagram. When the remote control is not working, first check the battery before, It may be loss.If it is good,so detect transmit infrared light device.However, because the human eye can not see infrared light,so can not know how good or bad.But the photo transistor can use to detect infrared light.  This circuit so use this photo transistor is the light receiver from the remote control.If it is nice to have the bias current of the transistor BC558.It runs a current flows through the LED,so the LED bright.The remote control that works correctly. The variable resistor VR1 is used to adjust the sensitivity of the circuit.  Remote control tester circuit diagram  

With a suitable load, the terminal voltage of a NiCd or lithium-ion battery is proportional to the amount of stored energy. This relationship, which is linear over a wide range, can be used to build a simple battery capacity meter. Circuit Image :   Voltage Tester for Model Batteries Circuit Image  This model battery tester has two functions: it provides a load for the battery, and at the same time it measures the terminal voltage. In addition, both functions can be switched on or off via a model remote-control receiver, to avoid draining the battery when it is not necessary to make a measurement. The load network, which consists of a BC517 Darlington transistor (T2) and load resistor R11 (15 Ω /5 W), is readily evident. When the load is active, the base of T1 lies practically at ground level. Consequently, T1 conducts and allows one of the LEDs to be illuminated. Circuit Diagram : Voltage Tester for Model Batteries Circuit Diagram The thoroughly familiar voltmeter circuit, whi...

When using a servo motor in a project, if the servo motor does not respond as per the input, how to make sure that the fault is not in the servo motor but the circuit or logic? One way is to isolate the servo motor from the circuit and check its proper working by feeding it pulses of varying width and checking the angle that the servo motor turns to. For example, a 1.5ms pulse should make the motor turn to a 90-degree position (neutral position). Circuit diagram: Servo Motor Tester Circuit Diagram The circuit presented here generates pulses of varying widths. It is built around two NE555 timer ICs (IC1 and IC2) and a few discrete components. Timer IC1 is configured as an astable multivibrator with a time period of 20 ms. Every 20 ms, the astable provides a very sharp negative pulse to trigger IC2. Timer IC2 is configured as a monostable multivibrator that produces 1ms, 1.5ms and 2ms long pulses to rotate the servo motor (M1). Pin 4 of IC1 is pulled down by resistor R2. When switc...

The circuit is very effective to test the remote controls what still works or not, the remote record will be tested using infra red. Examples of the TV remote, AC and others. Please try I am sure 100% will be successful. TV  Remote Tester Circuit The workings of the circuit is very simple, when the infra red sensor receive infrared signals pin 2 sensor will produce a voltage, this voltage will drives the PNP transistor so that the LED lamp and piezo disc (BZ) is active. for the power supply you can use a 9 volt battery and then use IC 7805 or use 1.5 volt batteries x 3 Following the specification of components installed Transistor BC557 TSOP 1738 Sensor Infra Red R1 = 10k ohm ¼ watt Resistor R2 = 1k ohm ¼ watt Resistor R3 = 1k ohm ¼ watt Resistor BZ = piezo disc led

Elco testing small to use AVO meters. But to distinguish between the elco elco 20.000uF/50V 2200uF/50V size would be very difficult, perhaps this phenomenon that makes creative hands itch to make elco with two label values. Scheme tool as follows, do not smile once, indeed simple. The cost to make it too cheap, not up to $ 1. Elco tester circuit The workings of this tool based on the nature of the condenser, the condenser ability to store electrons / voltage. Since each condenser has the characteristic charging time and discharging time is different for each size and type dielektrika. Ideally, the larger size, the greater the time required for charging and discharging (charging and disposal charges). How to use : Make sure the position of the switch (SW1) on the discharging position (position A). Connect / elco pairs that will be tested, then empty the contents briefly elco by pressing SW2 (approximately 1 to 3 seconds). Position the switch in the charging position (position B), the LE...

Suitable for any Infrared emitting device, 3V battery supply. A very simple device allowing a quick check of common Infra-red Remote-Controls can be useful to the electronics amateur, frequently asked to repair or test these ubiquitous devices. A reliable circuit was designed with a handful of components: the LED will flash when any of the Remote-Control push buttons will be pressed. The side of the Remote-Control bearing the IR emitting diode(s) must be directed towards the Photo Transistor (Q1) of the checker circuit: maximum distance should not exceed about 20 - 25cm. . Circuit Diagram:   Infrared Remote Tester Circuit Diagram Parts: R1 = 470K R2 = 47R D1 = LED Any Type Q1 = Photo Transistor Q2 = BC327 B1 = 3V Battery or 2 AA cell Notes: Current drawing of the circuit is less than 1mA when the LED illuminates and 0mA when no signal is picked-up by the Photo Transistor: therefore, SW1 can be omitted. SW1 will be SPST Toggle or Slider Switch