555-Circuits
This circuit is a simple -5V power supply using a 555 timer, designed for low-power analog applications involving FET operational amplifiers. The circuit converts +5V to -5V to create a dual power supply. It operates as a 555 astable multivibrator but is not suitable for high-efficiency designs and cannot handle heavy loads. It is appropriate for circuits with CMOS op-amps and A/D converters, but small battery designs should avoid this circuit. It is effective for powering analog amplifiers measuring voltages that swing around zero and can be utilized in portable measuring instruments powered by a rechargeable 9V battery. This dual 555 multivibrator functions as a power oscillator. The design is somewhat dated and may have errors, as documentation was not adequately updated after the design process. Additionally, this circuit can be adapted to create a small inverter for low-power 230V devices using a transformer in step-up mode, although it may generate noise if the transformer laminations are of poor quality. Modifications can include the use of a 7555 timer and switching transistors like the BD139 to drive a ferrite transformer, enabling the construction of a fluorescent lamp rated between 10W to 20W.
The circuit also includes a configuration for detecting objects using reflected infrared light, which can be enclosed in a cylindrical housing similar to an inductive proximity switch, making it useful as a level detector for colored liquids like oil. This design exhibits some immunity to ambient sunlight by detecting AC pulses. The 555 timer operates as an astable oscillator, rapidly flashing an infrared LED, which reflects off nearby objects along with ambient light.
Furthermore, the circuit demonstrates a voltage doubler using the 555 timer, which can provide a drive of up to 200mA from both Vcc and Gnd. The 555 timer’s mixed design capabilities allow it to function as a mini ADC due to its voltage-controlled oscillator (VCO) function, enabling applications in simple switching supplies and power line modems. It can also be used in various timer applications, including modulating signals and controlling relays.
Another application involves converting a voltage control output from a process controller into a current control signal for AC drives or valves. This three-wire voltage-to-current loop converter takes a 1-5V DC input, attenuates it, and feeds it to the LM723 op-amp, which maintains a voltage across a resistor, producing a constant current sink proportional to the input. The output can be calibrated from 1-5V to 4-20mA for connecting multiple instruments in series.
Additionally, the circuit incorporates a 555 monostable configuration, where a push switch triggers a reset pulse for a microcontroller. A diode is included for logical OR-ing, allowing high signals to pass while blocking low signals. The circuit also features a CD4093 Schmitt NAND-based flip-flop, which is favored for its design versatility.
The U1 7555 is a CMOS version of the 555 timer, configured in astable oscillator mode. Decoupling capacitors (C1 and C4) of 0.1µF ceramic disc type are used, with an output frequency of approximately 100kHz. The frequency stability can be enhanced by using a plastic or mica capacitor for C3, or a crystal oscillator for precise timing applications. The output from the 555 timer is fed to the clock input of a 4040 counter, enabling further signal processing within the circuit.This is a very simple -5V supply using one 555, useful for analog blocks using FET Opamps using low power. This circuit came up when i had to design limited by inventory. It worked well for its need. It converts Positive Five Volts to Negative Five Volts to create a dual supply. This +5 to -5 using a 555 Astable Multivibrator. is not a high efficie ncy design, in fact it cannot take a heavy load. Circuits having some CMOS Opamps and a A/D convertor is ok. Even very small battery designs must avoid this circuit. This suits well when you want to power an analog amp which has to measure voltages which swing on either sides of zero. It can be used in a LCD based portable measuring instrument running on a rechargeable 9V battery. This is dual 555 multivibrator like power oscillator. This is my contraption and conception but couple of decades old. It appears to have errors. It worked but the document fixing after design worked, not done. This can be used to make a small inverter, for powering 230V gadgets of low power. The transformer is used in step-up mode. It may make a sound if the laminations are not of good quality. This circuit can be modified using 7555 and switching transistors like BD139 driving a Ferrite 100 kHz transformer to build a Fluorescent Lamp of 10W to 20W.
From Schematics Read More This circuit is used to detect objects by reflected infrared light. It can be built into a cylindrical enclosure just like an inductive proximity switch. This is also useful as a level detector for colored liquids like oil. This has some immunity to ambient sunlight as it detects ac pulses. IC 555 is used as an astable oscillator and it flashes the Infra red LED D1 at a high speed, The object close to this LED reflects the light along with the ambient light which may also be sunlight. IR Led`s and Diodes The types available are various and polarity Read More This circuit shows the voltage doubler working with a 555.
LM555 has good drive 200mA, both Vcc and Gnd. 555 has the advantage of having a high drive as well as being a Mixed Design, Analog Programmable chip. That may be a High Title for such humble a chip. It has the capability of a Mini ADC due to its VCO function. It could form even a simple switching supply. Power Line Modems have been designed using this chip. Timers, Modulators, Trip Relays and even a Timer for The Humble Bread Toaster. Musical circuits, Piano and Metronome Galore, it drives Read More his Circuit converts a voltage control output from a Process Controller to be converted into a Current Control if the AC-Drive or Valve needs a Current Control Signal.
This is a three wire voltage to current loop converter. The 1-5 V DC is attenuated and fed to pin 5 LM723 opamp section which tries to maintain the same voltage at pin 10 across the 10 E, thereby producing a open collector constant current sink proportional to the 1-5V input. By trimming the attenuator you can scale-calibrate 1-5V input to 4-20mA output for looping many instruments in series, like a controller, Read More You must have read all the circuits and explanation on the other pages at delabs to understand this, as i cannot repeat the same thing as i have done it more than once already.
The circuit is a 555 monostable, The push-switch is to trigger and generate a reset pulse for uC. The diode is for OR` ing later. The High will go thru the diode but the Low of 555 cannot drink any current as diode blocks. The bottom part of the Circuit is the CD4093 Schmitt nand based flipflop. This is my favorite because of studying designs in Read More U1 7555 is a CMOS version of 555. The 555 here is in Astable Oscillator mode, C1 and C4 are decoupling capacitors 0. 1uF value, ceramic disc. The output is around 100kHz, If C3 is plastic or mica the frequency output will be stable with temperature. It is better to use a crystal oscillator. The 555 output is fed to clock input of 4040, the output of 555 w 🔗 External reference
The circuit also includes a configuration for detecting objects using reflected infrared light, which can be enclosed in a cylindrical housing similar to an inductive proximity switch, making it useful as a level detector for colored liquids like oil. This design exhibits some immunity to ambient sunlight by detecting AC pulses. The 555 timer operates as an astable oscillator, rapidly flashing an infrared LED, which reflects off nearby objects along with ambient light.
Furthermore, the circuit demonstrates a voltage doubler using the 555 timer, which can provide a drive of up to 200mA from both Vcc and Gnd. The 555 timer’s mixed design capabilities allow it to function as a mini ADC due to its voltage-controlled oscillator (VCO) function, enabling applications in simple switching supplies and power line modems. It can also be used in various timer applications, including modulating signals and controlling relays.
Another application involves converting a voltage control output from a process controller into a current control signal for AC drives or valves. This three-wire voltage-to-current loop converter takes a 1-5V DC input, attenuates it, and feeds it to the LM723 op-amp, which maintains a voltage across a resistor, producing a constant current sink proportional to the input. The output can be calibrated from 1-5V to 4-20mA for connecting multiple instruments in series.
Additionally, the circuit incorporates a 555 monostable configuration, where a push switch triggers a reset pulse for a microcontroller. A diode is included for logical OR-ing, allowing high signals to pass while blocking low signals. The circuit also features a CD4093 Schmitt NAND-based flip-flop, which is favored for its design versatility.
The U1 7555 is a CMOS version of the 555 timer, configured in astable oscillator mode. Decoupling capacitors (C1 and C4) of 0.1µF ceramic disc type are used, with an output frequency of approximately 100kHz. The frequency stability can be enhanced by using a plastic or mica capacitor for C3, or a crystal oscillator for precise timing applications. The output from the 555 timer is fed to the clock input of a 4040 counter, enabling further signal processing within the circuit.This is a very simple -5V supply using one 555, useful for analog blocks using FET Opamps using low power. This circuit came up when i had to design limited by inventory. It worked well for its need. It converts Positive Five Volts to Negative Five Volts to create a dual supply. This +5 to -5 using a 555 Astable Multivibrator. is not a high efficie ncy design, in fact it cannot take a heavy load. Circuits having some CMOS Opamps and a A/D convertor is ok. Even very small battery designs must avoid this circuit. This suits well when you want to power an analog amp which has to measure voltages which swing on either sides of zero. It can be used in a LCD based portable measuring instrument running on a rechargeable 9V battery. This is dual 555 multivibrator like power oscillator. This is my contraption and conception but couple of decades old. It appears to have errors. It worked but the document fixing after design worked, not done. This can be used to make a small inverter, for powering 230V gadgets of low power. The transformer is used in step-up mode. It may make a sound if the laminations are not of good quality. This circuit can be modified using 7555 and switching transistors like BD139 driving a Ferrite 100 kHz transformer to build a Fluorescent Lamp of 10W to 20W.
From Schematics Read More This circuit is used to detect objects by reflected infrared light. It can be built into a cylindrical enclosure just like an inductive proximity switch. This is also useful as a level detector for colored liquids like oil. This has some immunity to ambient sunlight as it detects ac pulses. IC 555 is used as an astable oscillator and it flashes the Infra red LED D1 at a high speed, The object close to this LED reflects the light along with the ambient light which may also be sunlight. IR Led`s and Diodes The types available are various and polarity Read More This circuit shows the voltage doubler working with a 555.
LM555 has good drive 200mA, both Vcc and Gnd. 555 has the advantage of having a high drive as well as being a Mixed Design, Analog Programmable chip. That may be a High Title for such humble a chip. It has the capability of a Mini ADC due to its VCO function. It could form even a simple switching supply. Power Line Modems have been designed using this chip. Timers, Modulators, Trip Relays and even a Timer for The Humble Bread Toaster. Musical circuits, Piano and Metronome Galore, it drives Read More his Circuit converts a voltage control output from a Process Controller to be converted into a Current Control if the AC-Drive or Valve needs a Current Control Signal.
This is a three wire voltage to current loop converter. The 1-5 V DC is attenuated and fed to pin 5 LM723 opamp section which tries to maintain the same voltage at pin 10 across the 10 E, thereby producing a open collector constant current sink proportional to the 1-5V input. By trimming the attenuator you can scale-calibrate 1-5V input to 4-20mA output for looping many instruments in series, like a controller, Read More You must have read all the circuits and explanation on the other pages at delabs to understand this, as i cannot repeat the same thing as i have done it more than once already.
The circuit is a 555 monostable, The push-switch is to trigger and generate a reset pulse for uC. The diode is for OR` ing later. The High will go thru the diode but the Low of 555 cannot drink any current as diode blocks. The bottom part of the Circuit is the CD4093 Schmitt nand based flipflop. This is my favorite because of studying designs in Read More U1 7555 is a CMOS version of 555. The 555 here is in Astable Oscillator mode, C1 and C4 are decoupling capacitors 0. 1uF value, ceramic disc. The output is around 100kHz, If C3 is plastic or mica the frequency output will be stable with temperature. It is better to use a crystal oscillator. The 555 output is fed to clock input of 4040, the output of 555 w 🔗 External reference