Showing posts with label how. Show all posts
Showing posts with label how. Show all posts
Monday, March 23, 2015
How to Make a Simple DC to DC Voltage Doubler Circuit Diagram Using IC 4049
The following circuit can be used for doubling any DC source voltage (up to 15 V DC). The presented design will double any voltage between 4 to 15 V DC and will be able to operate loads at current not more then 30 mA.
As can be seen in the diagram, this DC voltage doubler circuit employs just a single IC 4093 for achieving the proposed result.The IC 4093 has six gates in all which are all effectively for generating the discussed voltage doubling actions.
Two of the gates out of the six are configured as an oscillator. The extreme left of the diagram shows the oscillator section.
The 100 K resistor and the 0.01 capacitor form the basic frequency determining components.
A frequency is imperatively required if a voltage stepping actions needs to be implemented, therefore here too the involvement of an oscillator becomes necessary.
These oscillation become useful for initialing the charging and discharging a set of capacitors at the output which amounts to the multiplying of the voltage across the set of capacitors in a such a way that the result becomes twice the applied supply voltage.
However the voltage from the oscillator cannot be preferably applied directly to the capacitors, rather its done through a group of gates of the IC arranged in a parallel way.
These parallel gates together produce a good buffering to the applied frequency from the generator gates so that the resultant frequency is stronger with respect to current and does not falter with relatively higher loads at the outputs.
But still keeping the specifications of a CMOS IC in mind the output current handling capacity cannot be expected to be larger than 40 mA.
Higher loads than this will result in the deterioration of the voltage level toward the supply level.
The output capacitor values can be increased to 100uF for getting reasonably higher efficiency levels from the circuit.
With 12 volts as the supply input to the IC, an output of around 22 volts may be acquired.
Sunday, March 22, 2015
How to Make an Automotive Electronic Fuse Circuit
A fuse is a device used in electrical wiring for preventing accidental fire hazards due to to a short circuit or overloads. In ordinary mechanical type of fuses, a special fusible wire is used which melts when theres short circuit at some point in the wiring.
Though such fuses are fairly reliable, are surely not so efficient or elegant with their performance.
A mechanical fusible type of fuse requires careful selection as far as the rating is concerned and once blown, again requires careful replacement of the device correctly.
Even automobiles incorporate largely the above fusible types of fuses for the discussed precautions concerns.
However the above inefficient fuse can be very effectively replaced with more versatile types of electronic fuse circuit with little consideration.
The idea has been exclusively developed by me and the test results were pretty encouraging.
The CIRCUIT DIAGRAM is very simple, a relay is used to switch the battery power to the rest of the electrical of the vehicle via its contacts.
A low value resistor is place across the base emitter of a transistor for sensing the rise in the current levels.
When a possible short circuit is sensed, an equivalent amount of voltage is developed across the low value resistor, this voltage instantly instantly triggers the transistor which in turn triggers the relay driver stage.
The relay quickly reverts and switches OFF the supply to the vehicle electrical.
However in the process it also latches itself so that it does go into an oscillating mode.
The relay contacts must be rated to handle the maximum allowable current for the vehicle normal needs.
The value of the sensing resistor should be carefully selected for the intended tripping operations at the correct over load levels.
I used an iron wire (1mm dia. 6 turns) in place of the sensing resistor and it could handle well up to 4 amps after which it forced the relay to trip.
For higher currents lower number of turns may be tried.
The "push to OFF" switch is used to reset the circuit, but only after the short circuit condition is properly rectified.
A simple electronic fuse circuit developed by me is shown below:
Though such fuses are fairly reliable, are surely not so efficient or elegant with their performance.
A mechanical fusible type of fuse requires careful selection as far as the rating is concerned and once blown, again requires careful replacement of the device correctly.
Even automobiles incorporate largely the above fusible types of fuses for the discussed precautions concerns.
However the above inefficient fuse can be very effectively replaced with more versatile types of electronic fuse circuit with little consideration.
The idea has been exclusively developed by me and the test results were pretty encouraging.
The CIRCUIT DIAGRAM is very simple, a relay is used to switch the battery power to the rest of the electrical of the vehicle via its contacts.
A low value resistor is place across the base emitter of a transistor for sensing the rise in the current levels.
When a possible short circuit is sensed, an equivalent amount of voltage is developed across the low value resistor, this voltage instantly instantly triggers the transistor which in turn triggers the relay driver stage.
The relay quickly reverts and switches OFF the supply to the vehicle electrical.
However in the process it also latches itself so that it does go into an oscillating mode.
The relay contacts must be rated to handle the maximum allowable current for the vehicle normal needs.
The value of the sensing resistor should be carefully selected for the intended tripping operations at the correct over load levels.
I used an iron wire (1mm dia. 6 turns) in place of the sensing resistor and it could handle well up to 4 amps after which it forced the relay to trip.
For higher currents lower number of turns may be tried.
The "push to OFF" switch is used to reset the circuit, but only after the short circuit condition is properly rectified.
A simple electronic fuse circuit developed by me is shown below:
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