Voltage-doubler
#voltage-doubler
#relay driver
#power transistor
#12V power supply
#24V
#18V
#pnp
#npn
#voltage conversion
Description: This circuit operates relays rated for 24V and 18V DC using a 12V power supply. It can be implemented with a wide range of PNP or NPN power transistors. Components include: U1: NE 555 timer; C1 and C2: 50 pF, 25 VDC capacitors; Q1: TIP29, TIP120, 2N4922, TIP61, TIP110, or 2N4921 transistors; Q2: TIP30, TIP125, 2N4919, TIP62, TIP115, or 2N4918 transistors.
The described circuit is a relay driver that utilizes a 12V power supply to control relays operating at 24V and 18V DC. The core of the circuit is based on the NE 555 timer, which is configured in a monostable or astable mode depending on the desired operation. The NE 555 timer's output can be used to switch the power transistors, which in turn control the current flowing to the relay coils.
The inclusion of capacitors C1 and C2, rated at 50 pF and 25 VDC, serves to stabilize the circuit and filter any noise that may affect the performance of the timer and transistors. The choice of power transistors (Q1 and Q2) offers flexibility in terms of current handling and switching speed. The recommended transistors such as TIP29, TIP120, 2N4922, TIP61, TIP110, and 2N4921 for Q1, and TIP30, TIP125, 2N4919, TIP62, TIP115, or 2N4918 for Q2, provide a range of options suitable for different applications and load requirements.
When implementing this circuit, it is important to ensure that the transistors are adequately rated for the relay coil current and that appropriate heat sinking is used if necessary. The circuit can be further enhanced with flyback diodes across the relay coils to protect the transistors from voltage spikes generated when the relays are de-energized. This design is versatile and can be adapted for various control applications, making it a valuable addition to any electronic project involving relay control.This circuit drives relays of 24 and 18 Vde from a 12-V power supply. Use this circuit with almost any pnp or npn power transistor. Parts: Ul: NE 555 timer. Cl and C2: 50 p.F/ 25 Vdc. Q1: TIP 29, TIP120, 2N4922, TIP61, T!PllO, or 2N4921. Q2: TIP30, TIP125, 2N4919, TIP62, TIP115, or 2N4918.
The described circuit is a relay driver that utilizes a 12V power supply to control relays operating at 24V and 18V DC. The core of the circuit is based on the NE 555 timer, which is configured in a monostable or astable mode depending on the desired operation. The NE 555 timer's output can be used to switch the power transistors, which in turn control the current flowing to the relay coils.
The inclusion of capacitors C1 and C2, rated at 50 pF and 25 VDC, serves to stabilize the circuit and filter any noise that may affect the performance of the timer and transistors. The choice of power transistors (Q1 and Q2) offers flexibility in terms of current handling and switching speed. The recommended transistors such as TIP29, TIP120, 2N4922, TIP61, TIP110, and 2N4921 for Q1, and TIP30, TIP125, 2N4919, TIP62, TIP115, or 2N4918 for Q2, provide a range of options suitable for different applications and load requirements.
When implementing this circuit, it is important to ensure that the transistors are adequately rated for the relay coil current and that appropriate heat sinking is used if necessary. The circuit can be further enhanced with flyback diodes across the relay coils to protect the transistors from voltage spikes generated when the relays are de-energized. This design is versatile and can be adapted for various control applications, making it a valuable addition to any electronic project involving relay control.This circuit drives relays of 24 and 18 Vde from a 12-V power supply. Use this circuit with almost any pnp or npn power transistor. Parts: Ul: NE 555 timer. Cl and C2: 50 p.F/ 25 Vdc. Q1: TIP 29, TIP120, 2N4922, TIP61, T!PllO, or 2N4921. Q2: TIP30, TIP125, 2N4919, TIP62, TIP115, or 2N4918.
12V/1.5A Residential AlarmCircuit
The following alarm circuit is designed with features that may be suitable for residential and commercial alarm system applications. It has a 12V and 1.5A regulated power supply. Furthermore, this residential alarm circuit also includes a delay circuit, a 24-hour...
voltage conversion circuit composed of NJM4558
Figure 1-42 (a) is a voltage/current conversion circuit that converts a 0-10V input voltage into a 4-20mA output current. Adjusting resistor RP2 can set the input voltage (Ui) to 0V, resulting in an output current (I) of 20mA; similarly, setting...
24V to 36V Battery Charger Circuit
This 24V to 36V linear battery charger is long overdue. While this is an old circuit technique, it is optimized for charging higher voltage lead-acid batteries.
The 24V to 36V linear battery charger is designed to provide a stable charging voltage...
Dual Relay Driver Board Circuit Schematic
This relay driver enhances the input impedance using a standard BC547 NPN transistor (or its equivalent). It is a widely used driver capable of operating various relays, including reed relays. Transistors Q1 and Q2 function as a simple common-emitter amplifier,...
Dual Relay Driver Board Circuit
This circuit provides a straightforward and efficient method for interfacing two relays in switching applications. The relay driver utilizes a standard BC547 NPN transistor (or equivalent) to enhance the input impedance. It is a widely used driver capable of operating...
voltage conversion circuit composed of NJM4558
Figure 1-42 (a) is a voltage/current conversion circuit that converts a 0-10V input voltage into a 4-20mA output current. Adjusting resistor RP2 can set the input voltage (Ui) to 0V, resulting in an output current (I) of 20mA; similarly, setting...
Relay Driver with Strobe
The LM111 comparator can be utilized to design a relay driver with a TTL strobe, which enhances control over the relay driver. The strobe signal can be used to manage the relay operation more effectively.
The LM111 is a high-speed voltage...
PNP Transistor Analysis
The PNP transistor is the exact opposite of the NPN transistor discussed in the previous tutorial. In this type of transistor construction, the two diodes are reversed compared to the NPN type, resulting in a Positive-Negative-Positive configuration, with the arrow...
Another kind of relay driver board used to utilize your old PC
This article discusses the utilization of old PCs as simple controllers. Many obsolete systems, such as the 8088, 8086, 80286, 80386, and 80486, are no longer capable of running modern software, yet they can still function effectively. Often, individuals abandon...