As you know, some model cars "Lada", developed many years ago, largely inferior to their current counterparts. However, with a slight the cost of some service indicators old machines can be easily raised to quite modern. In this article, in particular, the described apparatus, allowing to increase the usability of the wiper and washer glass.
The unit is an electronic automatic control of motor wiper blade, interchangeable with existing Electromechanical car relay PC-154 (see the book Pyatkova, K. B., A. Ignatov, P. et al., "the Car family VAZ-2104, VAZ-2105: a Guide to maintenance and repair. - M.: "Behind the wheel", 1999, pp. 146 - 148). The main difference block as described in the journal earlier is that it allows you not only to adjust the frequency of stroke brushes within a wide range (down to zero) in intermittent, but also translates the wiper in the multi double moves when you press the lever stack-loonygames.
The core of the device (Fig. 1) the node that was assembled on the timer DA2. The timer is enabled by the model scheme generator, timing of which is determined by the elements R4, R5, R6, C3 in accordance with the expressions: tзC3= 0,693(R4+R5+R6)C3, tрC3= 0.693R4 C3, where HSS charging time of the capacitor C3 to the voltage 2Uпис/3; tрC3 - discharge time of the capacitor C3 to Epic/3 (it is assumed here that the engine the variable resistor R6 is in some intermediate position, and the contacts of the switch SF2, coupled with this resistor, shorted).
(click to enlarge)
At the time of filing on the power voltage of the capacitor C3 is discharged, the voltage the inputs R and S of the timer DA2 is zero, so that its internal trigger sets the output (pin 3) voltage is high. For this reason transistors VT1 and VT2 of the power amplifier are closed and the supply circuit of the motor wiper is switched off. The capacitor C3 begins to slowly charged through resistors R6, R5, R4. Through time
tзC3 the voltage across it reaches a level equal to 2Uпит/3, timer DA2 switches, at the high output level changes to low, the transistors opens, turn on the motor and starts the movement of the brushes.
Since then, the capacitor C3 will be quickly discharged through the exit open the collector (pin 7) of the timer and the resistor R4 as long as the voltage on it decreases to u n and m/z. then the timer DA2 returned to state, and the transistors will be closed. The brush will continue to move until the end double stroke (before returning to the starting position).
Time tрC3 chosen smaller than one double stroke brushes - 0,8 1,3..., but not less than 0.2 seconds (during this time shall be securely manage to close the contacts end switch wiper mechanism). A variable resistor R6 you can change the length of pause between two strokes of brushes.
The site, assembled on the timer DA1 and representing a single-shot controls the operation of the generator on DA2. In the initial state, the voltage at the inputs R and S timer DA1 and the capacitor C1 is close to the supply voltage, the output of timer low level, so the only generator node is not affected.
When you press the lever washer closed contacts SF1, turn on the pump, feed on the windshield washer fluid. The capacitor C1 is almost instantly discharged through the diodes VD1 and VD2, the voltage at the inputs R and S of the timer DA1 reduced practically to zero, and the output low level is changed to high. Through the diode VD3 and the resistor R3, capacitor C3 is charged up very quickly supply voltage, timer DA2 is switched to the zero state and open the transistors of the power amplifier. While the capacitor C3 remains charged, self-oscillating mode of the generator on a timer DA2 impossible.
When you release the lever washer contacts SF1 open ends the flow of the fluid, the capacitor C1 begins to charge through resistor R2, and at the moment when the voltage at the input R of the timer DA1 reaches 2Uпит/3, timer switches - the output will be low voltage, the capacitor C3 will be discharged and the timer DA2 will be back in self-oscillating mode. Time charging of the capacitor C1 is selected such that upon release of the lever washer wiper blades made 1-3 continuous double stroke.
Thus, a node that collected on DA1, translates the wiper in a continuous mode of operation when applied to the windshield washer fluid and returns it to intermittent through several double strokes brushes after releasing the lever washer reservoir. When you open contacts SF2 (wiper off) brushes the wiper can be set in motion only when you press the lever washer reservoir.
The current consumed by the unit inoperative wiper motor, not exceed 25 mA. Power to the unit is supplied in the translation installed on the machine the mode selector switch to the middle position ("Intermittent"). In extreme the provisions of the "Off" and "Continuous" unit is disconnected from the electrical system.
Structurally, the unit is mounted on two PCBs dimensions mm 65x30 foiled unilateral fiberglass thickness of 1.5 mm. Drawing boards it is shown in Fig. 2,a and b. Card set in plastic casing of the old relay RS-514. To do this, from foil fiberglass 1.5 mm thick) cut the cover of such size that it can be installed in the slots of the casing (foil inside) and remove. To the foil lid soldered the two boards on each of they provided a strip of foil is electrically connected to the common wire. The tabs on the cover features a printed conductors to the outside; the gap between the plates and the walls of the casing - 10... 15 mm.
In order to increase the stiffness of welded construction, the free edges of boards bind-cut rigid copper wire with a diameter of 1...1.2 mm, soldered in drilled this hole. The nodes are mounted on circuit boards are connected in single unit three jumper patch cord; the connection points marked letters A, B and C. the Numbers indicate the mounting pad, attached to the connectors X1 and x2.
As the pin part of the connector x2 pin used block from the relay RS-514, which are included in the appropriate socket carrier onboard network. On the diagram shows the colors of the wires of the on-Board network according to the above-mentioned book. Connector X1 - SG-3, SG-5, or any other suitable size. Diodes KDA you can replace any of the series KD, KD, KD, KD and KD105B - CD, CD, CD, D, D. Instead CTE ideal transistor with CT alphabetic indices L And M, or To any of the series CT, CT, and instead CTB - any of the series CT, KT static current transfer ratio base not less than 30. For other parts there are no special requirements.
To establish the unit instead of the electric motor is temporarily connected car the lamp power 5.. .21 W (contacts 2 and 4 of connector x2), and the operation of the lever washer mimic circuit output 1 common wire. From laboratory source serves voltage - plus on pin 1 of connector x2, minus - on contact 4.
Observing the duration of the flash lamp, choose the desired time relationship. Selection of resistor R2 sets the desired number of continuous double strokes brushes after releasing lever washer (if specified in the scheme face value it is three). Choose the resistors R5 and R6, setting accordingly the minimum and maximum pause between strokes of brushes in an intermittent mode. It is advisable to selection of resistors stopwatch to measure the time of one double stroke brushes.
Variable resistor R6 is placed under the instrument panel to the right of the steering column. Additional connector X1 allows you to quickly replace the unit for Electromechanical relay and back.
If after installing the unit on the motor brushes when applying power remain fixed, you should replace the transistor VT2 another with a higher static the current transfer ratio base.
Author: D. Sauri, Moscow