Showing posts with label controller. Show all posts
Showing posts with label controller. Show all posts
Monday, September 15, 2014
Reservoir Pump Controller Wiring diagram Schematic
This schema operates an automotive windLcd washer pump to fill a 20-litre drum from a 205-litre water reservoir. The drum is suspended above a drip line, which irrigates a vegetable garden. Two stainless steel probes mounted in the drum act as sensors for the system. One probe is positioned at the high water mark, the other at about half-full. The pump power is switched by a 12V automotive relay (RLY1). Two op amps (IC1a & IC1b) connected as voltage comparators form the basis of the schema.
Initially, assume a falling water level with the pump switched off. When the water level exposes the lower probe, the non-inverting input (pin 5) of IC1b rises to about 7.4V. With trimpot VR2 correctly adjusted, this will be higher than the voltage on pin 6. The output (pin 7) therefore swings high, biasing Q1 into conduction. This in turn causes Q4 to conduct, switching on the relay and starting the pump.
In addition, when Q4 switches on it supplies base current to Q3 via a 6.8kO resistor. Initially, this current flows through the 47µF capacitor, but once its base-emitter voltage reaches about 0.6V, Q3 conducts. This action latches Q4 in the "on" state, as its base current can flow to ground via Q3 when Q1 stops conducting – which will occur when the rising water level reaches the low probe. When the water level reaches the high probe, the voltage on the non-inverting input (pin 2) of IC1a decreases markedly due to the conductivity of the water.
Reservoir Pump Controller Circuit Diagram
If trimpot VR1 is correctly adjusted, the output (pin 1) swings high, switching on Q2. This discharges the 47µF capacitor and robs Q3 of its base current, switching this transistor off. This in turn switches off Q4 and the relay. The zener diodes and 1kO series resistors at the probe inputs protect the op amp’s high impedance inputs from the effects of static discharge. The 47µF capacitor in parallel with the base-emitter junction of Q1 prevents the latching function from being activated when power is applied to the schema. The author’s setup is powered from an old car battery charged from a 12V solar panel.
Source by : Streampowers
Sunday, September 14, 2014
NES Controller
The article will guide you on how to use NES controller in Atari 2600 or ZX Spectrum using an Arduino. Read through the entire article to have a better idea. An arduino and a few connectors are the only components involved here. Since the source code is small, any Arduino board can be utilized. The detailed list of components involved is mentioned below:
- Arduino
- DB-9 Male connectors – 2 nos
- DB-9 Female connector
- 5 Leds for the test dongle
- 5 resistors 330 Ohms 1/4 Watt for the test dongle
- Connecting wires
The DB-9 female plus wires can be replaced by a used Atari Joystick cable if required. The NES cable also can be cut and connected to the arduino. But the wires should be identified without any confusion. The source code is compiled and uploaded to the Ardunio. IDE version 0.22 was used to develop the code. In order to observe the exact behavior of the schema, a dongle has to be used before the schema is conneced to the ATARI. Buttons on the NES controller are used to activate the LEDs in the dongle.
The Arduino board has to be powered if a dongle is used for testing the schema. The joystick controller provides the necessary power that is required for the Arduino to function. No external power is required in this case. This marks the end of the design and testing. The controller is now complete and ready for use.
The Arduino board has to be powered if a dongle is used for testing the schema. The joystick controller provides the necessary power that is required for the Arduino to function. No external power is required in this case. This marks the end of the design and testing. The controller is now complete and ready for use.
Friday, September 5, 2014
Automatic Speed Controller for fans Coolers
During summer nights, the temperature is initially quite high. As time passes, the temperature starts dropping. Also, after a person falls asleep, the metabolic rate of one’s body decreases. Thus, initially the fan/cooler needs to be run at full speed. As time passes, one has to get up again and again to adjust the speed of the fan or the cooler.The device presented here makes the fan run at full speed for a predetermined time. The speed is decreased to medium after some time, and to slow later on. After a period of about eight hours, the fan/cooler is switched off.Fig. 1 shows the schema diagram of the system. IC1 (555) is used as an astable multivibrator to generate clock pulses. The pulses are fed to decade dividers/counters formed by IC2 and IC3. These ICs act as divide-by-10 and divide-by-9 counters, respectively. The values of capacitor C1 and resistors R1 and R2 are so adjusted that the final output of IC3 goes high after about eight hours.The first two outputs of IC3 (Q0 and Q1) are connected (ORed) via diodes D1 and D2 to the base of transistor T1.
It can be seen that initially the fan shall get AC supply directly, and so it shall run at top speed. When output Q2 becomes high and Q1 becomes low, relay RL1 is turned ‘off’ and relay RL2 is switched ‘on’. The fan gets AC through a resistance and its speed drops to medium. This continues until output Q4 is high. When Q4 goes low and Q5 goes high, relay RL2 is switched ‘off’ and relay RL3 is activated. The fan now runs at low speed.Throughout the process, pin 11 of the IC is low, so T4 is cut off, thus keeping T5 in saturation and RL4 ‘on’. At the end of the cycle, when pin 11 (Q9) becomes high, T4 gets saturated and T5 is cut off. RL4 is switched ‘off’, thus switching ‘off’ the fan/cooler.Using the schema described above, the fan shall run at high speed for a comparatively lesser time when either of Q0 or Q1 output is high. At medium speed, it will run for a moderate time period when any of three outputs Q2 through Q4 is high, while at low speed, it will run for a much longer time period when any of the four outputs Q5 through Q8 is high.If one wishes, one can make the fan run at the three speeds for an equal amount of time by connecting three decimal decoded outputs of IC3 to each of the transistors T1 to T3. One can also get more than three speeds by using an additional relay, transistor, and associated components, and connecting one or more outputs of IC3 to it.
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