Retour menu des cours · Retour menu des montages. Logo. Amateur and Short Wave Radio Electronics Experimenter’s Web Site. SWL Page. Au cours des premiers stade s, on définit, à partir d’un circuit préalablement étudié, oscillateur à quartz 45 MHz – ampli différentiel porte s – multivibrateurs. Download scientific diagram | Multivibrateur monostable à amplificateur opérationnel. from publication: Electronique des impulsions | | ResearchGate, the .
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Kind code of ref document: The circuit has a first capacitor and a second capacitor storing electric charges. A coupling unit electrically couples a first terminal of each capacitor to zero electric potential and a second terminal of each capacitor to electric potential equal to Vcc in a first state, and electrically couples the first terminal of the second capacitor to an output terminal of the circuit in a second state.
A control unit controls a passage of a state corresponding to the first state or second state to another state corresponding to the second state or the first state. Independent claims are also included for the following: The invention relates to a voltage multiplier circuit, used for example for electrically powering one or more LED Light Emitting Diode from an input voltage lower than a threshold voltage of the at least one LED. The voltage multiplier circuit is advantageously used for flashing one or more LEDs.
It is sometimes the problem of having to supply power to a load, for example an LED, from a voltage that is not enough to feed properly continuously charging. For example, the voltage ignition threshold of a LED is relatively high: The current through the LED depends on the voltage applied to its terminals and the brightness obtained is substantially linear injected current when the voltage at its terminals is greater than its threshold voltage.
Thus, a photovoltaic cell generally delivers a voltage of around 0. To increase the value of a voltage, it is known to use switched-capacitor circuits. A multivibrator is used for varying the voltage across the capacitance. When it is desired to output a voltage higher than twice that applied to the input, this involves having several capacitors switched in cascade.
But in this case, the losses become very important in terms of diodes disposed between capabilities. Moreover, such a cascading works very poorly at low voltage because it is necessary to generate phase signals. Finally, saturation phenomena also disrupt the operation of such a system. To increase the value of a voltage, it is also known to use circuits called “boost-converter” or “step-up converter”, which conventionally use an inductor and a flop to operate.
A very low consumption as is the case for the power of an LED power supplythis type of circuit is not effective for not only the yield is low, but the circuit also consumes a lot of load current for example of the order of about 1 mA.
Les Trois Physiciens – Henri Abraham – Éditions Rue d’Ulm
An object of the present invention is to provide a voltage multiplier circuit for multiplying, for example, a factor of about 3 an input voltage, to power an electric load, for example an LED, from a low input voltage, for example lower than the LED threshold voltage, consuming less power than the circuits of the prior art, that is inexpensive to produce and which has a small footprint.
For this, the invention provides a multiplier circuit of a voltage Vcc to be applied to at least a first input of the circuit, comprising at least: There is also provided a multiplier circuit of a voltage Vcc to be applied to at least a first input of the circuit, comprising at least: The multiplier enables in a first phase corresponding to the first state, to electrically charge capacity using the input voltage Vcc, then, in a second phase corresponding to the second state, using the pump phenomenon capacity loads so that the load e.
By repeating these two phases, it is thus possible to blink an LED for example at very low frequencies, consuming the least possible energy thanks to the absence of inductance in this circuit. The multiplier is used to apply to the terminals of the load voltage in the form of a “flash”, that is to say for a short time, which allows for example to illuminate an LED for a time corresponding to the voltage decay time in the LED threshold voltage.
The circuit according to the invention allows, for example, from a power source supplying a voltage Vcc equal to about 1 V, to turn on a LED normally requires a voltage of 3 V to emit light.
Le circuit peut fonctionner avantageusement avec une tension Vcc comprise entre environ 0,8 V et 1,8 V. The circuit may advantageously operate with a voltage Vcc between about 0.
The coupling means, or electrical connection means may include: The control means may comprise a second input circuit for receiving a control signal. The first multjvibrateurs means may comprise a CMOS inverter to be electrically powered by the voltage Vcc, the second input of the circuit can be electrically connected to an input of said CMOS inverter and an output of said CMOS inverter may be electrically connected to the first terminal of the first capacity.
In this case, the second and third connecting means may each comprise a switch for being controlled by a signal delivered on the output of the CMOS inverter of the first connecting means. The fourth connection means may comprise a CMOS inverter to be electrically powered by the voltage Vcc, the first terminal of the first capacitor can be electrically connected to an input of the CMOS inverter of the fourth connection mulgivibrateurs and an output of the CMOS inverter of the fourth connecting means is electrically connected to the second terminal of the second capacitor.
The second connection means may comprise a CMOS inverter comprising at least two MOS transistors whose sources can be electrically connected to multivbrateurs electric potential Vcc and the first output terminal of the circuit, the second terminal of the first capacitor can be electrically connected to a output of the CMOS inverter of the second connection means and the first terminal of the first capacitor can be electrically connected to an input of the CMOS inverter of the second connecting means.
The third connection means may comprise a CMOS inverter comprising at least two MOS transistors whose sources can be electrically connected to the zero electric potential and the second output terminal of the circuit, the first terminal of the second capacitor may be electrically connected multigibrateurs a output of the CMOS inverter of the third connection means and the second terminal of the second capacitor may be electrically connected to an input of the CMOS inverter of the third connection means.
EPB1 – Dispositif pour l’électrothérapie à basse fréquence – Google Patents
Les moyens de couplage et les moyens de commande peuvent comporter: The coupling means and the control means may include: The invention also relates to an electronic device comprising at least: The electrical load may include at least one LED. In this case, the voltage output from the multiplier circuit may be higher than multigibrateurs LED threshold voltage.
Le dispositif peut comporter en outre: Ckurs device may further comprise: The power supply means may comprise photovoltaic energy conversion means coupled to at least mjltivibrateurs capacity capable of storing energy supplied by the conversion means and to provide the terminals of said capacitor voltage Vcc.
Such supply means allow the device to be fully autonomous and does not require maintenance no battery replacement, for example.
Means for converting photovoltaic energy and the energy storage capacity converted form an energy storage system having the particular advantage compared to an electrochemical battery, to avoid rapid degradation of the storage performance of energy over time storage capacity may be effective on at least one million cycle, unlike a battery whose performance is generally degraded from one thousand cycles and does not require to monitor voltages and the electric charge performed monitoring in order to avoid overload and deep discharge in the case of a battery.
The energy storage capacity converted can have a capacity greater than about 0. Such capability has the particular advantage of occupying a very small volume typically of about 1 cm 3 per Farad. The photovoltaic energy conversion means may comprise at least one photovoltaic cell, or one or more PIN diodes instead of the photovoltaic cell which are of very small dimensions a few mm 2.
Alternatively, the power supply means may comprise at least one stack. In another variant, the power supply means may comprise at least one capacitor capable of storing electric charges from the control signal. The second control means may comprise at least one oscillator or a multivibrator, and may be coupled to the power supply means and to the multiplier circuit.
The electrical load may include a plurality of LEDs and at least one multiplexer adapted to alternately couple each of the LEDs with the first and second output terminals of the multiplier circuit. In this case, the multiplexer may be coupled to at least one binary counter adapted to control the coupling between the plurality of LEDs and one of the first and the second output terminal of the multiplier circuit.
It is thus possible a chase successively lighting the different LEDs. The invention also relates to a method of multiplying a voltage Vcc, comprising at least the steps of: Steps a and b may be repeated sequentially, the output voltage can be applied to terminals of at least one LED. The invention will be better understood from reading the description of embodiments given purely indicative and non-limiting with reference to the accompanying drawings, wherein: Identical, similar or equivalent parts of the different figures described below have the same numeric references so as to facilitate the passage from one figure to another.
The different parts shown in the figures are not necessarily to a uniform scale, to make the figures more legible. The various possibilities variants and embodiments must be understood as not being exclusive of each other and can be combined together.
Vcc aux bornes d’une chargeici une LED. The circuit functions here as a symmetrical charge pump to approximately triple the value of a supply voltage Vcc and to apply this voltage equal to about 3. Vcc across a loadhere an LED. When the switches, and are adapted to be controlled by a value of another signal, the voltage multiplier circuit may include means for adapting the value of the control signal depending on the value for to be received by the switches, and The first capacitor has a first terminal, or end, electrically connected to a first switchand a second terminal electrically connected to a second switch The second capacitor has a first terminal electrically connected to a third switch and a second terminal electrically connected to a fourth switch During the charging phase of capacity andthe four switches, and are in a switching state such that the capacities and each having their first terminal electrically connected to the electric potential Vcc and the second terminal electrically connected to a zero electric potential such as ground.
La tension de 3. Thus, just after the passage of the switches, and from the first state to the second state, a tripled voltage relative to the supply voltage Vcc is applied across the LED The voltage being 3.
Vcc greater than the threshold voltage of the LED which may be between about 1. During this discharge, the LED is electrically powered and emits light radiation whose duration corresponds to the duration of discharge capacity and until it reaches the threshold voltage of the LED After the voltage across the LED has become less than the threshold voltage of the LEDthe switches, and fro in the first state, for charging the capacities andand the ring 1 state – 2nd state is repeated in order to flash the LED The durations of the charge phase and discharge capacities andthat is to say, the durations of the states in which are located the switches, and will depend on the frequency of the control signal This control signal may for example be a square wave of frequency equal to about 0.
The four switches, and for simultaneous control, that is to say the coupling means of the circuit may be formed as a single component, corresponding for example to TS3A circuit manufactured by Texas instruments which operates from a voltage equal to about 1.
The value of the voltage Vcc may be adapted and correspond to the minimum voltage at which the component forming the four switches, and operates.
The switches, and are preferably of the type “break-before-make”, that is to say that during a transition from a first state to a second state, the electrical connection formed in the first state is open before switching and form the electrical connection of the second state, thereby avoiding unwanted short circuits that may multuvibrateurs the consumption of the multiplier circuit As the circuit described above, the multiplier circuit forms a symmetrical charge pump that is triple the value of a supply voltage Vcc and to apply this triple voltage across the LED Multivibrateura first inverter has an output connected to the drains of the two MOS transistors of the inverter electrically connected to the first cous of the first capacitor and to an input of the second inverter corresponding to the gates of two NMOS transistors and Multicibrateurs transistors of the second inverter An output of the second inverter electrically connected to drains of the two MOS transistors of the second inverter is electrically connected to the second end of the second capacitor The control multivibraateurs controlling the switching of the second and third switches and corresponds to the signal obtained at the output of the first inverterand thus corresponds to the inverse signal to that applied to the input of the first inverter This zero potential signal is also applied to the input of the second inverter The second inverter thus delivers on its output a signal potential equal to Cuors, the potential being applied to the second terminal of the second capacitor Vcc being applied across the LED during the transition from first to second state.
As the switches andcouts and preferably have a property of type “break-before-make” resulting in a time lag of the control signals of the MOS shipments N and P.
This time lag can be obtained via several inverters or capacity to offset these signals in time. Alternatively, it is possible that only one of switches or is replaced by a CMOS inverter.
Such as and previously described circuits, circuit forms a symmetrical charge pump that is triple the value of a supply voltage Vcc applied at the input of circuit With respect to circuitthe second and third switches and are replaced by two CMOS inverters andcalled third and fourth inverters. An output of the fourth inverter connected to the drains of the two MOS transistors multovibrateurs the fourth inverter is electrically connected to the first end of the second capacitor As above, the CMOS inverters and may have a property such as “break-before-make”.
EP2544345A1 – Voltage multiplier circuit – Google Patents
The different inverters can be cojrs by MOSFET embodying the switching from one state to another as described previously in the circuit. Alternatively, it is possible that only one of the switches and is replaced by a MOS inverter. In addition, one or two CMOS inverters and may be replaced by one or both switches and These resistors can limit the current load capacityand avoid any sudden voltage drop in the voltage multiplier circuit, linked to excessive inrush currents on the voltage source at the time of switching.
The device also comprises supply means supplying the voltage Vcc is electrically connected to control means able to deliver on an output a oscillating control signal between two distinct values, for example corresponding to an oscillator or a multivibrator, providing the control signal to the voltage multiplier circuit These means comprise a photovoltaic celle.
La tension Vcc est fournie sur une coure des moyens d’alimentation