Showing posts with label relay. Show all posts
Showing posts with label relay. Show all posts
Saturday, September 13, 2014
Sound Activated Lamp Relay Switch Circuit
This simple Sound-Activated Lamp schema shown int the schematic diagram actives the switch using sound. We can use this schema for various applications, such as automatic (sound-controlled) disco light or car’s LED light show. The Q1 amplify the audio from mic. The R1 is used to adjust the peak of signal to greater than about 0.7 volts, act as sensitivity adjuster. A certain level, the signal coming from microphone, after amplification by Q1, will trigger the SCR and light lamp I1. If we change the lamp with a relay, then we can get a sound-activated relay/switch, which can be used to control more powerful / high wattage high voltage lamps. If we use a relay, place a 1N4007 diode in parallel with the relay coil to prevent the back-emf from relay coil destroying the SCR.
Sound-Activated Lamp Circuit Diagram
Friday, September 5, 2014
Build a Carrier Operated Relay Wiring diagram Schematic
Carrier-Operated Relay Circuit Diagram shows a COR/CAS schema for repeater use. CR1 is a silicon diode. 2 may be any relay with a 12-V coil (a long-life-reed relay is best). R2 sets the length of time that K2 remains closed after the input voltage disappears (hang time). shows a timer schema. Values shown for Rl and CI should provide timing up to four minutes or so. CI should be a low-leakage capacitor; Ql is a silicon-controlled rectifier, ECG-5452 or equivalent.
Kl may be any miniature relay with a 12-volt coil. The timer is reset when the supply voltage is momentarily interrupted. The switch must be in the reset position for the remote reset to work. This schema operates from the detector output of a receiver. A delay schema is included so that the relay stays closed for a time period after the carrier output from the receiver disappears.
Carrier-Operated Relay Circuit Diagram
Monday, August 25, 2014
Solid State Relay Circuit Diagram
Solid state relay is a series that functions like a relay hibryd mechanics. Solid state relays is built with insulating an MOC for separate the input and the switch. With Solid state relays we can avoid the occurrence of sparks as it did in the relay can also avoid the occurrence of conventional connection is not perfect because porous contactor as in conventional relays.
The series of solid state relays This is quite simple and we can make in a PCB hole. For more details can be seen in the picture following a series of solid state relays.
The series of solid state relays This is quite simple and we can make in a PCB hole. For more details can be seen in the picture following a series of solid state relays.
| Solid State Relay Circuit Diagram |
Solid state relay has many advantages including no mechanical friction on the contactor, the connection process only occur when there are crosses zero, there is no spark at the contactor, not noisy, small konsusi flow control, better endurance.
Saturday, August 16, 2014
Simple Relay Step Up Circuits
Have you ever needed to power a 12-volt relay in a schema but only had 6 or 9 volts available? This simple schema will solve that problem. It allows 12-volt relays to be operated from 6 or 9 volts, or 24-volt relays from 12 volts. While most normal relays require the manufacturer-specified coil voltage to reliably pull the contacts together, once the contacts are together you only need about half that rated voltage to hold them in. This schema works by using that principle to provide a short burst of twice the supply voltage to move the contacts and then applies the available 6 or 9 volts to the relay to lock the contacts in place.
With reference to Figure A., when the main supply is applied to the schema the 220-µF capacitor, C1, charges quickly to +6 volts through resistor R3. The schema is now awaiting voltage on the control input. When a control voltage (can be as little as 3 volts) is applied to the control input, transistor T1 switches on. The other transistor, a BC558, is also switched on. This allows connection of the relay coil to the main supply rail while T1 shorts the positive terminal of the 220-µF capacitor to ground. Now the negative terminal of the capacitor is at a potential of –6 volts. This is applied to the other side of the relay coil. The relay coil potential is then briefly 12 volts — enough to actuate the contact(s).
However, the coil voltage drops to the supply voltage fairly quickly. The period is determined by the R-C time constant of the relay coil resistance and the 220-µF capacitor. While this schema is simple and works well in many situations, it has a few weaknesses in its current form. The relay may remain energized for as long as one second after the control input has fallen. Also, if the control input goes high before the capacitor has fully recharged, it may not have enough energy to control the relay reliably. Also, the voltage drop across the diode limits the voltage to about 10.8 volts.
The more complex version of the schema shown in Figure B fixes these problems by using an extra transistor and diode. In this arrangement, the BC558 is now isolated from the recharge current of the capacitor. The new transistor provides fast charging for the capacitor. Charging is completed within the mechanical response time of the relay. When using these diagram it should be noted that the contact pressure of the relay contacts may be al little lower than with the nominal coil voltage. It is therefore advisable to keep contact currents well below the maximum specified value.
The more complex version of the schema shown in Figure B fixes these problems by using an extra transistor and diode. In this arrangement, the BC558 is now isolated from the recharge current of the capacitor. The new transistor provides fast charging for the capacitor. Charging is completed within the mechanical response time of the relay. When using these diagram it should be noted that the contact pressure of the relay contacts may be al little lower than with the nominal coil voltage. It is therefore advisable to keep contact currents well below the maximum specified value.
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