Avt 594 User manual

The device is perfectly suited to any audio amplifier

equipped with a standard 'manual' potentiometer.

This circuit can be controlled by virtually any infrared

remote control, requiring only a simple remote code

memorisation procedure. It was tested with several

pilots from different televisions, decoders, DVDs and

audio equipment - with each it worked properly.

Any button on the remote control can be assigned to

one specific function: turn left (volume down), turn

right (volume up) or on/off. This makes it possible to

use remote control buttons normally not used.

The controller is a versatile circuit. After the exchange

of the potentiometer for a geared motor, it can

control, for example, window blinds.

Characteristics

• remote control by any infrared remote control

• simple teaching mode for remote controller

• ability to assign any remote control keys for three

functions:

- turn anticlockwise

- turn clockwise

- control of integrated relay (e.g., ON/OFF)

• power supply: 12 VDC

• remote control and potentiometer with motor

included

Electrical diagram of the circuit is shown in Figure 1.

The controller is built on an 8-lead microcontroller

ATtiny45, which is equipped, among other things,

with a non-volatile EEPROM where codes will be

stored for individual commands that control the

circuit operation. Components R2, C2 are

responsible for resetting the processor during power

on. The microcontroller does not require any

external quartz resonator as it has an integrated RC

generator. The TFMS5360 infrared receiver is

connected to the PB4 input of the processor. Light

emitting diode D1 is used to signal the status of

relay PK1 controlled by transistor T7 from output

PB2 of the processor, it also has a useful function

when teaching codes sent by the remote control.

This circuit must be supplied with a DC voltage of

approx. 14 VDC. The digital part of the device is

stabiliser. Each received command coming from the

transmitter is analysed by the processor. If it

corresponds to one of the predefined commands,

the motor is set in motion for the time specified by

the transmission time and in set direction. Each

received command assigned to relay PK1 changes its

state to the opposite. The relay type RM96 is

designed for switching currents of up to 8 A, which

Circuit description

Remote-Controlled Potentiometer

For Audio Applications

AVT 594

kits

PDF

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ASSEMBLY DIFFICULTY

Fig. 1 Schematic diagram

Fig. 2 Arrangement of components on the PCB.

Arrangement of the components on the PCB is

shown in Fig. 2. Start mounting the circuit from

soldering resistors on the board, processor socket,

capacitors and finish by mounting the transistors,

infrared receiver and relay, if you choose to use it.

Figure 3 shows the controller leads. Module

assembled from proven components requires no

adjustment, and once the commands sent by the

remote control have been recorded it is

immediately operational.

ATtiny45

in most cases is enough to activate amplifier

circuits. Diode D2 protects transistor T7 from the

effects of surges occurring on the relay coil at the

time of switching off. The executive part is a typical

bidirectional DC motor controller, whose operation

is controlled by two digital signals. The motor was

incorporated in a diagonal bridge formed by power

transistors of type BD139 and BD140. Appearance

of a high state at the PB0 output of US1 will

polarise transistor T5, as well as transistors T4 and

T1. Current will flow through the path: +power

supply, transistor T1, motor winding , transistor T4

and power supply ground. Motor connected to the

CON1 connector will start to rotate in one

direction. Similar situation takes place if the

transistor T6 is polarised, except that the motor

starts to rotate in the opposite direction.

Mounting and start-up

Teaching remote codes

To save control commands in the memory,

jumper JP1 must be shorted for about 5 seconds.

The teaching mode will be signalled by the LED

on, and after you remove the jumper, the LED will

start flashing, then the potentiometer will turn

slightly anticlockwise. Now, the circuit waits for

two commands from remote control, which will

be responsible for reducing the volume level. In

Supply

12 VDC

Teaching

jumper

Infrared

receiver

Signal

ground

Signal

output

Signal

input

Not

connected

Indicator

light

Fig. 3.

most cases, you want that only one button had this

function, so it had to be pressed twice. Such action

is needed for correct operation with some remote

controls. After each correctly received code, the

diode is longer on. After the second code, the

potentiometer will turn clockwise to signal the next

configuration step - increasing the volume level,

you must now press twice (each time after

confirmation by the circuit) corresponding key on

your remote control. After this action, the relay will

switch on briefly, which is an incentive to enter the

command responsible for its switching on. Once all

six commands have been received, the circuit will

return to normal operation with new settings.

List of components

Resistors

R1:..............................................................................100 Ω

R2:..............................................................................10k Ω

R7, R8, R9, R10, R11,R12:...................................300 Ω

R3:..............................................................................220 Ω

R4: ................................................................................1 kΩ

R5, R6, R13:...............................................................2 kΩ

Capacitors

C1, C3:.........................................................100 uF / 16V

C2:...................................................................4,7 uF /16V

Semiconductors

US1: ......................................................................Attiny45

US2:.............................................................................7805

US3: ..............................................TFMS5360 or similar

T1, T2:......................................................................BD140

T3, T4:......................................................................BD139

T5, T6, T7: ...............................................................BC547

D1:..................................................................................LED

D2:..........................................................................1N4148

Other

PK1:.........................................RM96P12 or equivalent

JP1: ...........................................Jumper + goldpin 1×2

ARK2/500

ARK3/500 3.5mm

Rotary potentiometer with motor

Any infrared remote control

Notes

AVT SPV reserves the right to make changes without prior notice.Installation and connection of the appliance not in accordance with the instructions, unauthorised modification of

components and any structural alterations may cause damage to the appliance and endanger persons using it. In such a case, the manufacturer and its authorised representatives shall

not be liable for any damage arising directly or indirectly from the use or malfunction of the product.

The self-assembly kits are intended for educational and demonstration purposes only. They are not intended for use in commercial applications. If they are used in such applications, the

purchaser assumes all responsibility for ensuring compliance with all regulations

This symbol means do not dispose of your

product with your other household waste.

Instead, you should protect human health

and the environment by handing over your

waste equipment to a designated collection

point for the recycling of waste electrical

and electronic equipment.

Leszczynowa 11 Street,

03-197 Warsaw, Poland

https://sklep.avt.pl/

AVT SPV Sp. z o.o.