Showing posts with label speed. Show all posts
Showing posts with label speed. Show all posts
Tuesday, November 11, 2014
TDA1151 based Motor Speed Controller circuit with explanation
This motor speed controller uses a TDA1151 monolithic integrated circuit , designed by ST Microelectronics . TDA1151 motor speed controller circuit is designed in a SOT-32 plastic package and can be used for small applications where the space inside is very critical .
Also this circuit diagram can be used as speed regulator for DC motors of record players, tape and cassette recorders, movie cameras, toys or other low cost applications.
This speed controller circuit can provide a high output current up to 800 mA without any additional components and has a low quiescent current of 1.7mA .
The TDA1151 require a low reference voltage ( around 1.2 volts ) and it has a excellent parameters stability versus temperature .
The maximum voltage that can be applied to the TDA1151 is around 20 volts .
As you can see in the circuit diagram the TDA1151 require just few common external components and is very easy to design .
Source: electroniq.net
Saturday, November 8, 2014
Efficient Fan Speed Controller
A partial solution to quietening noisy PCs can be to reduce the speed of internal cooling fans. Low-cost fan speed controllers are available, but they often employ inefficient, heat-generating linear regulators and contain no temperature feedback mechanism. This idea makes use of a readily available, cheap in-car mobile phone charger. The majority of these use common circuitry and require only minor modifications to operate as efficient fan speed controllers complete with temperature feedback. Most in-car chargers are based on the well-known MC34063 DC-DC switchmode IC.
When used for charging mobile phones, the open-circuit output voltage is typically set to between 7V and 9V. This is achieved with a simple voltage divider across the output, the centre point of which connects to the feedback input (pin 5) of the MC34063. To make the output voltage var-iable with air temperature, first replace the upper resistor of the divider with a 4.7kΩ resistor in series with a 4.7kΩ trimpot. The lower half of the divider is then replaced with a 470Ω resistor in series with a 500Ω NTC thermistor. These values are only a guide and can be varied to suit different thermistor and fan types.
Efficient Fan Speed Controller Circuit Diagram
Note that component lead length should be minimised to avoid introducing noise into the feedback circuitry. Getting the correct fan starting voltage is a matter of trial and error. The values shown on the circuit give a starting voltage of about 6.8V at room temperature but trimpot VR1 can be used to raise this voltage as necessary. The output can then rise to about 10V if the interior temperature rises sufficiently. The 4.7kΩ resistor could be reduced to 3.9kΩ and VR1 adjusted to give a lower starting voltage if the fan speed is still too high at 7V. After running for one hour or so, the fan voltage as set by the interior case temperature thermistor on my PC settled at 7.4V.
Suitable chargers are available from Oatley Electronics, Cat. No. 2D0074. They’re currently listed at $5 for two, which is less than the price of the MC34063 ICs alone! Data on the MC34063 can be downloaded from www.onsemi.com and a useful development aid is to be found at www.nomad.ee/micros/mc34063. Finally, note that not all chargers have an output filter capacitor installed. Typically, this is a 220µF 10V or 16V electrolytic type. To save a few cents, the manufacturers sometimes leave this component out, relying on the mobile’s battery to perform the filtering task. If this component is missing from your charger’s PC board, it should be installed before the supply is used.
Tuesday, September 2, 2014
HOW TO ADJUST Carburetor Engine Speed WACKER NEUSON GENERATOR GP 3800 GP GPS 5600 GP GPS 6600
* Start the engine and allow it to warm up to operating temperature.
* Set the pilot screw (a) two turns out.
* With the engine idling, turn the pilot screw (a) in or out to the setting that produces the highest rpm.
* After the pilot screw is adjusted, turn the throttle stop screw (b) to obtain the standard idle speed.
Note: On some engines the pilot screw is fitted with a limiter cap (c) to prevent excessive enrichment of the air-fuel mixture in order to comply with emission regulations. The mixture is set at the factory and no adjustment should be necessary. Do not attempt to remove the limiter cap. The limiter cap cannot be removed without breaking the pilot screw.
Adjusting Engine Speed
Generators require a fixed engine speed to maintain the correct voltage. Engine speed is controlled by a governor which automatically adjusts to varying loads on the engine to maintain a constant speed. There is no throttle control.
To set the engine to the proper speed:
Turn the speed adjusting screw (b) in or out to obtain a no-load speed.
NOTICE: Setting the engine speed too high or too low may damage tools and other appliances attached to the generator.
Electrical Schematic - GP 2600
Electrical Schematic - GP 3800, GP/GPS 5600, GP/GPS 6600 CAN Models
Components - GP 3800, GP/GPS 5600, GP/GPS 6600 CAN models
CLICK ON THE PICTURES TO ZOOM IN
Sunday, August 24, 2014
Efficient Fan Speed Controller Wiring diagram Schematic
A partial solution to quietening noisy PCs can be to reduce the speed of internal cooling fans. Low-cost fan speed controllers are available, but they often employ inefficient, heat-generating linear regulators and contain no temperature feedback mechanism. This idea makes use of a readily available, cheap in-car mobile phone charger. The majority of these use common schemary and require only minor modifications to operate as efficient fan speed controllers complete with temperature feedback. Most in-car chargers are based on the well-known MC34063 DC-DC switchmode IC.
When used for charging mobile phones, the open-schema output voltage is typically set to between 7V and 9V. This is achieved with a simple voltage divider across the output, the centre point of which connects to the feedback input (pin 5) of the MC34063. To make the output voltage var-iable with air temperature, first replace the upper resistor of the divider with a 4.7kΩ resistor in series with a 4.7kΩ trimpot. The lower half of the divider is then replaced with a 470Ω resistor in series with a 500Ω NTC thermistor. These values are only a guide and can be varied to suit different thermistor and fan types.
Efficient Fan Speed Controller Circuit Diagram
Note that component lead length should be minimised to avoid introducing noise into the feedback schemary. Getting the correct fan starting voltage is a matter of trial and error. The values shown on the schema give a starting voltage of about 6.8V at room temperature but trimpot VR1 can be used to raise this voltage as necessary. The output can then rise to about 10V if the interior temperature rises sufficiently. The 4.7kΩ resistor could be reduced to 3.9kΩ and VR1 adjusted to give a lower starting voltage if the fan speed is still too high at 7V. After running for one hour or so, the fan voltage as set by the interior case temperature thermistor on my PC settled at 7.4V.
Suitable chargers are available from Oatley Electronics, Cat. No. 2D0074. They’re currently listed at $5 for two, which is less than the price of the MC34063 ICs alone! Data on the MC34063 can be downloaded from www.onsemi.com and a useful development aid is to be found at www.nomad.ee/micros/mc34063. Finally, note that not all chargers have an output filter capacitor installed. Typically, this is a 220µF 10V or 16V electrolytic type. To save a few cents, the manufacturers sometimes leave this component out, relying on the mobile’s battery to perform the filtering task. If this component is missing from your charger’s PC board, it should be installed before the supply is used.
Source by : Streampowers
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