Now in individual households are increasingly using chainsaws Ural-electron" and "Friendship-4-electron", which engines are equipped with electronic the ignition module. This unit is a very simple scheme, but, like other equipment, sometimes fails. Replace it with a new one - a simple matter, but in the sale it is rare, especially in rural areas, and costs a lot. Ham fully able to repair the unit.
The ignition unit is specified chainsaws referred to as a unified contactless magneto. It is made in the form of briquettes, of the cured transparent epoxy resin, which flooded the site, which includes most of the details block.
After the following repairs, the unit will transtorno-capacitor. His scheme widely known (see figure). From the previous block used high voltage the transformer T1, the generator coil L1, coil-ignition sensor and L2 the capacitor C1.
During rotation of the flywheel with the magnets in the coil L1 is induced by the alternating current a voltage of about 400 V. It straighten diodes VD1, VD2. Pulsating voltage charges the capacitor C1.
At some point in time during the rotation of the flywheel L2 in the sensor pulse appears current, which, passing through the diode VD3, opens SCR VS1. As a result through the primary winding of ignition coil T1 elapses bit current pulse of the capacitor C1 and the secondary - there is a pulse of high voltage, causing spark discharge in spark ignition in the engine cylinder.
Used the details of the previous block is not required to disassemble - they remain on their places. You only need to release their findings from the compound. To do this snap, as the compound is transparent and not too hard, but it should work very carefully so as not to damage the findings and their isolation.
Diodes VD1 and VD2 are soldered directly to the released the findings of such a way that after installation of the flywheel he did not touch parts and conductors. SCR VS1 and a Zener diode mounted on a small bracket from fiberglass or Micarta and put it in a sturdy box suitable sizes. The box is attached by screws to the housing of the chainsaw and is connected to the block three wires in secure isolation. The wire is inserted into the three holes with a diameter of 4 mm who need to drill into the engine block near the ignition module.
The experiments show that the triacs CAN steady work in the winter conditions at temperatures down to -40 °C. Zener DA can be replaced DB or DW. Diodes - any of a series of CD or other for direct current and reverse voltage of at least 100 mA and 400 V, respectively.
If I needed to replace the capacitor C1, will fit any paper or film with a capacity of 0.5 to 1 µf for a voltage of less than 600 V.
Establishing the unit does not require.
Author: Ivanov, Viliuisk, Yakutia-Sakha