12v RELAY ON 6V SUPPLY

This circuit allows a 12v relay to operate on a 6v or 9v supply. Most 12v relays need about 12v to "pull-in" but will "hold" on about 6v. The 220u charges via the 2k2 and bottom diode. When an input above 1.5v is applied to the input of the circuit, both transistors are turned ON and the 5v across the electrolytic causes the negative end of the electro to go below the 0v rail by about 4.5v and this puts about 10v across the relay.

Alternatively you can rewind a 12v relay by removing about half the turns.

Join up what is left to the terminals. Replace the turns you took off, by connecting them in parallel with the original half, making sure the turns go the same way around
 
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6V Power Supply With 12V Relay

6V Power Supply With 12V Relay Circuit

Description :

This ambit allows a 12v broadcast to accomplish on a 6v or 9v supply. Most 12v relays charge about 12v to "pull-in" but will "hold" on about 6v. The 220u accuse via the 2k2 and basal diode. When an ascribe aloft 1.5v is activated to the ascribe of the schema, both transistors are angry ON and the 5v beyond the electrolytic causes the abrogating end of the electro to go beneath the 0v abuse by about 4.5v and this puts about 10v beyond the relay.

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Simple 500W 12V to 220V Inverter Circuits Wiring diagram

Simple  500W 12V to 220V Inverter Circuits Diagram. This is a Simple  500W 12V to 220V Inverter Circuits Diagram which produces an AC output at line frequency and voltage. 12VDC to 220V 50Hz inverter schema will power 220V or 110V appliances from 12V car battery. The schema is easy to make and is low cost. Use proper transformer. 

 The output (in watts) is up to you by selecting different power rating transformer and power transistor rating. If you load electronic device which require 120V AC, then use transformer with 120V in output. 

Simple  500W 12V to 220V Inverter Circuits Diagram

 

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22W Amplifier for 12V Power Supply Systems

This is a 22-W Amplifier schema that is designed for or 12-V DC power supply Systems. There are many application for  this schema,  such as in car audio  application. In car electrical  power supply system, the 12V power supply will be provided by the host vehicle’s battery. 

The capacitor C3 is used to give ripple rejection, since noisy power supply voltage is common in automotive electrical system. The power supply noise signal on car power supply is decoupled by the capacitors C2 and C1.  Smaller capacitor C2 is needed to decouple the high frequency noise, since the larger cap (C1) usually has high equivalent series inductance that prevent the high frequency noise  (such as glitch or spike) to be bypassed. 

The capacitors C5 couple the incoming audio signal to IC1 while decoupling static DC offset. For better bass response, this schema prevent rolling off of the low audio frequencies by choosing a relatively large capacitance for small signal, 10μF capacitors. Here is the schematic diagram of the  schema.

 22W Amplifier for 12V Power Supply Systems Circuit Diagram

This schema prevent power supply pop noise by muting the amplifier at the power-up. The mute input (pin 14) is fed by capacitor C6 and Resistor R1, giving delay on power-up which prevent  turn-on pop. This  R/C time constant gives about 1.4s delay to keep the output muted,  enough to make sure the amplifier reach the stable state after powered up.  

About how this muting works, the amplifier will be ON if pin 14 has at least 8.5 V. The chip will remain in muted condition if the voltage at this pin is below 3.3V.  This input pin need very low current consumption, only about 100 pA for standby (muted)  and around 40 pA when active. The R1 values must be no larger than 100,000  Ω. The R1/C6 constant should be on the second order. If time constant is too short, the turn-on pop will still be heard, but too long  time constant will give unpleasant delay.

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12V 3A Power Supply Wiring diagram Schematic

This schema provides a 12V regu-lated power supply with output current up to 3 amperes. It is spe-cially designed for use with 2m handheld rigs with linear power amplifier and CB portable QRP rigs. The schema uses monolithic IC CA3085 voltage regulator in 8-lead TO-5 package.  Its salient features include good load and line regulation, output current up to 100 mA (which can be increased to several amperes with additional pass transistors), output short-schema protection, and lower input voltage.  A low power dissipation is achieved by driving external series-pass transistor 2N4241 (T1) from  pin 2 of CA3085.

Circuit diagram :

12V, 3A Power Supply Circuit Diagram

Normal output pin 8 is returned to ground via diodes D3 and D4 to ensure error am-plification operation in the linear region. Ripple rejection is approximately 50 dB on no load and 35 dB on full load.  A 2x2x2.5cm aluminium heat sink fas-tened onto a 1.5mm blackened aluminium sheet of 12.5cm2 area on 2N4241 helps the schema in dissipating heat without ex-ceeding maximum device ratings. CA3085 can dissipate up to 650mW power in free air, without any heat sink.  AFCO-make C-05-4 heat sink is suitable for this IC. An improper heat sink may cause device junction temperature to ex-ceed the limit, resulting in progressive deterioration of the device. 

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