Description

Electronic control unit for fan (PSA)

This electronic control unit (ECU) is an alternative, improved version instead of the failed original one, as well as non-original. The warranty on the ECU is 1 year.

The major improvements:

• Polarity reverse protection.
• Two powerful transistor output stages.
• Improved heat sink and resistance to mechanical damage due to solid aluminum-based board.
• Improved anti-corrosion protection due to silicone casting compound.

A more detailed description of the features and differences:

PSA_Type3_depiction-1

PSA_Type2_depiction

The board has an aluminum base and heat-conducting dielectric about 0.1 mm thick. The thermal conductivity of the used insulating dielectric is 4 … 5 times higher than the FR-4 (textolite) dielectric. Aluminum base, dielectric and copper coating constitute a single structure and don’t exfoliate from each other under the aggressive influence of the environment. The original scheme uses a thin textolite board glued to an aluminum base. The thermal conductivity is much worse than that of a solid board with an aluminum base. Because of the poor heat sink in the original scheme, the control key often fails due to overheating. Under the influence of corrosion, vibration and temperature changes, the original board peels off from the aluminum base, which makes the whole scheme unusable.

1. Two powerful keys. Reliability and service life increase due to the distribution of currents and temperatures. There is only one key in the original scheme.
2. The key for protection against reverse polarity. (There is no protection against polarity reversal in the original scheme. Changing the polarity without the correct fuse in the circuit of the original scheme will lead to its failure).
3. Protection (600W 10 / 1000µs) against power surges over 18V for driver and microcontroller power supply circuits. (There is no such protection in the original scheme).
4. The core material is used with fewer losses than in the original one.
5. The throttle for filtering noise in the driver power supply circuit. (There isn’t such throttle in the original scheme).
6. The throttle for filtering noise in the microcontroller power supply circuit. (There isn’t such throttle in the original scheme).
7. To suppress inductive emissions of reverse polarity, a more powerful diode is used than in the original scheme.
8. A specialized driver for MOSFET keys is used. (In the original scheme a cheaper version is used assembled from separate SMD elements).
9. A larger number of filter capacitors is used to suppress impulse noise than in the original scheme.
10. Copper power paths of a larger area are used to reduce the resistance to high currents.
11. The whole scheme is filled with a special silicone compound, which becomes elastic as rubber when solidified. This prevents the ingress of moisture to electronic components even after a long period of operation. (The original scheme is filled with poor-quality compound, which eventually cracks and exfoliates. This results in corrosion damage to electrical components and open areas of the board).

The features that are present in both the following and the original PSA fan control schemes:

A) highly reliable microcontroller for the use in the automotive industry and designed for temperatures from -40 to + 125 ° С.

В) Protection circuits against overcurrent.

С) Overheat protection circuit.

D) Protection circuit protects against overvoltage and prevents the battery from completely discharging under reduced voltage.

Original non-working ECUs	The alternative, improved ECU	Original electric motors with alternative ECU, after repair
1500-500	ECU after 2007 (350-1)	after 2007 (With new ECU)

OriginalECU_Type2

ECU 2002-2007 with (350)

2002-2007 (With new ECU)

Instructions for installing the module