Single-channel remote control

In this project we'll see how to build a single-channel remote control. It 's a project easy to do : by using a radio module pre-assembled, we will get a card compact without sacrificing performance major. The insert function allows Nutchip impossible to obtain with a remote commercial: here are some suggestions from our readers. timer function : with a remote button, the relay remains energized for a time. mixed-function : two buttons switch on and off the relay, the third on for a short time, the fourth for a long time. delay function : By pressing the button on the remote, the LED lights now, but the relay is activated only after some time.The schematic includes a few components. In addition to Nutchip (IC1) trovialmo rel? a transistor with its pilot (TR1), an LED (DL1), and the radio receiver module (RX1). The ?-RESET pin connected to an external RC delay network driven by a dedicated integrated (IC3), a Motorola MC34064. With this integrated there will be no problems even in case of blackouts or brownouts, when the available voltage on the power supply might be insufficient to bring values ??to the proper functioning of Nutchip, if your application is not critical, or if you can guarantee continuous availability of 5V, then you can omit IC3. The other terminals of the board need to give the 5 Volt power supply stabilized (M1) and the output relay contacts (M2). On M2 are both normally closed (NC) and one normally open (NO) relay, which basically functions as a switch. The relay is energized by activating the output OUT4 Nutchip. The transistor TR1 amplifies the current output of the relay moves to the required (up to 50 mA). The guilty must be with a 5 Volt coil and the output contact must have a voltage and current proportional to the load to drive. For example, to light a bulb, 220V and 100W will be adjusted with a relay coil and contacts from 5Vdc to 250Vac 5A. The handling of household usually needs to add an external contactor or Servorelay great power. For this scheme we have designed a single sided PCB, which you can achieve ein house following the figure. You can also use a matrix board, building the tracks with lengths of copper wire: in fact the pitch used for the disposal of its components is of 2.54 mm and is indicated by squares visible in the picture. The assembly is not particularly difficult. It should, however pay close attention to the direction of insertion of the components, because there are many who may be exchanged or inserted upside down. For example IC3 is very similar to the transistor TR1, and IC1, the form RX1, the diode D1 and the LED DL1 are symmetrical potentially at risk of being inserted upside down! For any doubt always consult the page of components. Also careful not to reverse the + and - 5V power supply stabilized, if you will not have disastrous consequences. The capacitors C2 and C3 are used to "clean up" the voltage from any radio interference that dovvessero slip into the receiver and the Nutchip. The diode D1 protects the transistor from current peaks that are generated on the coil of the relay at the time of dropout. The diode DL2 instead serves as a warning: you turn drive the output OUT1 Nutchip. Usually comes on to indicate the status of the relay, but being driven by a separate output, nothing prevents you to use it regardless! The data come from the OUT pin of the receiver and enter the pin REMOTE Nutchip, ready to be decoded. You can upload the truth table in Nutchip just before inserting it into the circuit, but we find it more convenient when the Nutchip is already loaded on the card. For this reason we have included the programming connector CN1. visit page.