Showing posts with label using. Show all posts
Showing posts with label using. Show all posts
Friday, 6 June 2014
Wireless Sensor Applications using Dorji’f DRF5150S and DRf4432S Modules
Dorji Applied Technology from China builds different types of RF modules that can be easily incorporated in designing wireless data loggers, sensor network, telemetry and other wireless applications.
Some of their RF modules have an additional pre-programmed microcontroller that allows direct interface of selected analog and digital sensors to the module. This means you don’t need any external MCU or to write codes for these sensors. In this tutorial, Raj from Embedded Lab talks about their DRF5150S and DRF4432S RF modules which are very versatile and easy to use for wireless sensor applications. For illustrative purpose, Raj shows how to put them together to construct a simple wireless sensor application where data from a remote sensor are received and displayed on a PC, without using any external microcontrollers.
Friday, 17 May 2013
Car Subwoofer filter using OP Amp IC TL072
Here is the circuit diagram of simple and easy subwoofer filter which will be operated from a 12V DC supply. Such a circuit is incredibly helpful in Car subwoofer applications. The circuit is nothing however a low pass filter whose pass frequency will be adjusted between 60 to 160 Hz.
The circuit is intended round the TL072 twin BIFET opamp IC. Out of the 2 opamps within the chip, IC1A is wired as a buffer. The left and right audio inputs when mixing is fed to the input of the IC1A using the DPDT switch S1. Switch S1 is that the section control switch which might be used to create the subwoofer in section with different speakers.
When S1 is in position {2, 180 degree phase shift are induced.POT R7 will be used for controlling the level. IC1B forms the low pass filter whose pass frequency will be controlled by adjusting the twin gang POT R13.
When S1 is in position {2, 180 degree phase shift are induced.POT R7 will be used for controlling the level. IC1B forms the low pass filter whose pass frequency will be controlled by adjusting the twin gang POT R13.
Wednesday, 3 April 2013
RING BELL ELECTRONIC CIRCUIT USING NE555 DIAGRAM
RING BELL ELECTRONIC CIRCUIT USING NE555 DIAGRAM
This circuit produces oscillating frequency around 1kHz, and able to be converted by changing the value of resistor R1. The speaker will produce a long beep sound with 1kHz frequency. Here is the schematic :
Parts list :
- Resistor R1 : 10k ohm
- Resistor R2 : 56k ohm
- Capacitor C1-C2 : 0.01 uF
- Polar capacitor C3 : 1 uF/15V
- IC timer : NE 555
- Speaker : 8 ohm 0.5 W
- ON/OFF switch
- 5-15V Power supply
Sunday, 31 March 2013
Super Sensitive Intruder Alarm Circuit Using 741
Here is the description of the circuit diagram of an ultra sensitive intruder alarm. The shadow of an intruder passing few meters nearby the circuit is enough to trigger the alarm. The circuit is work based on the 741IC as the core of the system. This is the figure of the circuit.
Here IC2 uA 741 is wired as a sensitive comparator, whose set point is set by R6 &R7. The voltage divide by LDR and R9 is given at non inverting pin of IC2. The LDR can be housed in a dark tube to increase sensitivity. At standby mode these two voltages are set equal by adjusting R9.Now the out put (pin6) of comparator will be high. Transistor Q1 will be off. The voltage at trigger pin of IC1 will be positive and there will be no alarm. When there is an intruder near the LDR the shadow causes its resistance to increase. Now the voltages at the inputs of comparator will be different and the out put of IC2 will be low. This makes Q1 on. This makes a negative going pulse to trigger the IC1 which is wired as a mono stable multi vibrator. The out put of IC1 will be amplified by Q2 (SL 100) to produce alarm. The sensitivity is very important here. If you cannot adjust the required sensitivity properly, use one LOW resistance (~1K ) POT in series with R9 for fine adjustment. To setup the alarm, power up the circuit and adjust R9 so that LED D1 goes off.
Here IC2 uA 741 is wired as a sensitive comparator, whose set point is set by R6 &R7. The voltage divide by LDR and R9 is given at non inverting pin of IC2. The LDR can be housed in a dark tube to increase sensitivity. At standby mode these two voltages are set equal by adjusting R9.Now the out put (pin6) of comparator will be high. Transistor Q1 will be off. The voltage at trigger pin of IC1 will be positive and there will be no alarm. When there is an intruder near the LDR the shadow causes its resistance to increase. Now the voltages at the inputs of comparator will be different and the out put of IC2 will be low. This makes Q1 on. This makes a negative going pulse to trigger the IC1 which is wired as a mono stable multi vibrator. The out put of IC1 will be amplified by Q2 (SL 100) to produce alarm. The sensitivity is very important here. If you cannot adjust the required sensitivity properly, use one LOW resistance (~1K ) POT in series with R9 for fine adjustment. To setup the alarm, power up the circuit and adjust R9 so that LED D1 goes off.
Wednesday, 27 March 2013
How to Make a LED Chaser cum Blinker Circuit Using IC 4017
The presented circuit was requested by Mr.Joe, one of the keen followers of this blog. The circuit initially was intended to be used for generating LED strobe light effects and was asked to be modified such that it could be used as an LED sequencer as well as a blinker. The change over would be implemented via a toggle switch.
The circuit diagram may be understood with the following points:
The IC 4017 is not new to us and we all know how versatile and competent this device is. Basically the IC a Johnson’s decade counter/divide by 10 IC, fundamentally used in applications where sequencing positive output signals are required or desired.
The sequencing or the orderly shifting of the outputs take place in response to a clock pulse that needs to be applied at the clock input pin #14 of the IC.
With every rising positive edge of the clock input, the IC responds and pushes its output’s positive from the existing pin out to the next pin out in the order.
Here a couple of NOT gates are used as a oscillator for providing the above clock pulses to the IC 4017. VR1 may be adjuted for determining or fixing the speed of the sequencing.
The outputs of the IC are connected to an array of LEDs in a specific order which makes the LEDs look like as if they are running or chasing during the operations.
If the circuit would be required only to produce the chasing effect, the diodes would not be required, however as per the present ask the diodes become important and allows the circuit to be used as a blinker also, depending upon the position of the switch S1.
When the switch S1 is positioned at A, the circuit behaves like a light chaser and produces the normal chasing effect over the LEDs which start illuminating in sequence from top to the bottom, repeating the operations as long as the circuit remains powered.
As soon as S1 is flicked toward B, the clock signals from the oscillator are shifted into the input of the transistor T1, which instantly stats to pulsate all the LEDs together in response to the received clocks from N1/N2 configuration.
Thus as per the requirement we have successfully modified an ordinary light chaser circuit with an additional feature through which the circuit now is also able to function as a LED flasher.
Do not forget to connect the inputs of the remaining unused gates from the IC 4049 either to the positive or the negative of the supply. The supply pins of the IC 4049 also need to be connected to the relevant supply rails of the circuit, kindly refer to the datasheet of the IC.
Tf all the ten outputs of the IC 4017 are required to be integrated with LED sequencing, just connect pin #15 of the IC to ground and use the left over outputs of the IC for the required sequencing of the LEDs in the order of: 3,2,4,7,10,1,5,6,9,11
Parts List
The fooliwng parts will be needed for making this LED light chaser cum flaher circuit:
R1, R2, R3 = 1K,
VR1 = 100K linear pot.
All LED resistors are = 470 Ohms,
All diodes are = 1N4148,
All LEDs = RED, 5mm or as per choice,
T1 = 2N2907, or 8550 or 187,
C1 = 10uF/25V
C2 = 0.1uF,
IC1 = 4017,
N1, N2 = IC4049
Monday, 25 March 2013
How to Measure AC Milli volts Using IC 741 Circuit Diagram
The circuit shown below can be used to measure DC potentials in the range of milli-volts. The circuit is highly sensitive and is calibrated to measure voltages in the range of 1 mV minimum to 1 V maximum.
Measuring potentials in the order of milli-volts is generally difficult using ordinary multimeters. The circuit shown here can be used for sensing minute AC signals in the range of as low as 0.1 mV.
The transistors Q1 and Q2 has been configured as high gain feedback kind of amplifier, with the shown components the amplifier stage has been foxed to produce a gain of 100.
The next stage which consists of two 741 ICs, IC1 and IC2, have been wired up as precision rectifiers.
These together are able to generate a gain of 10 over bandwidth that might extend above 50kHz or below 20 Hz.
The over all gain of the circuit therefore falls in the range of 1000, which makes it imperative to have signals below 1mV well attenuated.
The setting of the circuit does not involve much of complication, just the preset RV1 needs to be adjusted initially for making the connected meter show a zero when there no signal at the input.
All resistors marked with asterisk must be 1% rated, MFR types.
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