TURN SIGNAL SWITCHER

TURN SIGNAL SWITCHER

This is quite simple but may at first be confusing for MGA owners and mechanics. Notice the picture of the back end of the vacuum regulated turn signal switch for the MGA (and some other cars of the era). The terminal designations molded into the housing are "F", "L", and "R".

For the MGA 1500 the "F" can mean Flasher. For the MGA 1600 the "F" can mean Fuse. This is the power input terminal for the switch. The "L" and "R" terminals would seem to be labeled for Left and Right turn signals, but for the MGA this is backward, where "L" is connected to operate the Right turn signal and "R" is connected to operate the Left turn signal.

This seemingly odd terminal labeling likely originated with an earlier application where the manual input knob, shaped like a single wing, was installed with the wing oriented upward from the shaft. Then when you push it toward the left the shaft would rotate anti-clockwise, and toward the right would rotate clockwise. That is the direction of rotation required for these terminal designations to make sense.

As this switch is installed in the MGA, the wing on the knob hangs downward. Pushing it to the left makes the shaft rotate clockwise, and to the right rotates anti-clockwise. This means you have to hook up the Left turn signal wire to the "R" terminal, and the Right turn signal wire to the "L" terminal. If your MGA turn signals seem to work backward, this is likely the problem and the fix. When in doubt, use a test light or ohm meter to check continuity for the switch terminals when you operate the input knob. Also pay attention to the color coding on the wires.

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Valentine Heart Project schema

Valentine Heart Project schema

This project flashes 18 LEDs at three different rates and you can use these to create an eye-catching Valentine Heart. The circuit is kept simple (and low cost) by using the 4060B IC which is a counter and oscillator (clock) in one package. The circuit requires a 9V supply, such as a PP3 battery. It will not work with lower voltages and a higher voltage will destroy the LEDs.

The preset variable resistor can be used to adjust the oscillator frequency and this determines the flash rate of the LEDs. The IC limits the current to and from its outputs so the LEDs can be safely connected without resistors in series to limit the current. The stripboard part of the circuit is easy to build but the wiring for the LEDs needs care so detailed instructions are provided below.

You can download our Valentine Heart template to print out and glue onto thick card, hardboard etc.

The Valentine Heart template is supplied as a PDF file. To view and print PDF files you need an Acrobat Reader which may be downloaded free for Windows, Mac, RISC OS, or UNIX/Linux computers. If you are not sure which type of computer you have it is probably Windows.

Warning!

Using a battery (or power supply) with a voltage higher than 9V will destroy the LEDs.

You can see from the circuit diagram (below) that 6 LEDs are connected in series between the +9V supply and 0V. Each LED requires about 2V across it to light, so using a voltage of about 12V (= 6 × 2V) or more will make the LEDs conduct directly, regardless of the 4060B IC. With no series resistor to limit the current this will destroy the LEDs.

Parts Required

resistors: 10k, 470k

preset: 47k (this could be 100k if necessary)

capacitor: 0.1µF

4060B IC

16-pin DIL socket for IC

LEDs × 18, 5mm diameter, red (or any mix of red, orange, yellow and green)

on/off switch

battery clip for 9V PP3

stripboard 13 rows × 18 holes

Stripboard Layout

Building the Circuit

Begin by soldering the components onto the stripboard as shown in the diagram above. Do not insert the 4060B IC at this stage.

Arranging the LEDs:

Cut out a suitable shape from stiff card (or similar material), such as the Valentine Heart template. Paint or colour the card at this stage if necessary.

Plan the layout of the 18 LEDs (suggested positions are marked on the template).

Drill 5mm holes for the LEDs - put the card on a piece of scrap wood to do this without damaging the card or the table.

Push LEDs into the holes, they should be a fairly tight fit and glue should not be necessary.

Label the LEDs D1 - D18 at random on the back of the card.

Wiring of the LEDs:

Use stranded wire for all the connections to the LEDs and solder all wires near to the LED body so the leads can be trimmed short later on.

The wire colours are suggested to avoid confusion but you can use other colours if you wish, the electricity won't mind! For example you could use red and black as suggested but substitute yellow and white for the blue and green suggested.

Cut all the LED short leads to be very short to make identification easier:

Connect RED wire to link up all the LONG leads of D1, D2 and D3.

Remember to solder wires near to the LED body so the long lead can be trimmed short later on.

Connect BLACK wire to link up all the SHORT leads of D16, D17 and D18.

Use 3 pieces of BLUE wire to connect:

D7 short - D10 long

D8 short - D11 long

D9 short - D12 long

Use 12 pieces of GREEN wire to connect:

D1 short - D4 long

D4 short - D7 long

D2 short - D5 long

D5 short - D8 long

D3 short - D6 long

D6 short - D9 long

D10 short - D13 long

D13 short - D16 long

D11 short - D14 long

D14 short - D17 long

D12 short - D15 long

D15 short - D18 long

Connect the RED wire from the circuit board to the RED wiring on the Valentine heart (connect it to any convenient point).

Connect the BLACK wire from the circuit board to the BLACK wiring on the Valentine heart (connect it to any convenient point).

Connect the 3 BLUE wires from the circuit board to each of the 3 BLUE wires on the Valentine heart, they may be connected in any order.

Carefully check all wiring.

Trim the long LED leads.

Plug the 4060B into its holder.

Connect a 9V battery and switch on.

Using a small screwdriver, adjust the 47k preset variable resistor to give a suitable flash rate for the LEDs.

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Rangkaian delay speaker amplifier-Audio amplifier output relay delay

you can get the advantage by using this circuit it that: if there is a relationship fuse x speakers with amplifier circuit will be disconnected immediately, so that the speaker is safe from disaster.waktu waiting or delay time is approximately 5 seconds, and can be altered by changing capacitor C2 elco with more value small. The time needed to re-open relay if the current cut off about 0.5 secondscomponent tobuilt this : C1 100 uF 40V electrolytic C2 100 uF 40V electrolytic D1 1N4007 D2 1N4148 Q1 BC547 R1 33 kohm 0.25W R2 2.2 kohm 0.25W RELAY 24V DC relay, coil resistance >300 ohm

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