August 2009

Description: This device was designed upon request and enables the sequential operation of four LEDs in either the left or right direction. This functionality is achieved using a 7555 CMOS timer IC (IC1) configured as an astable multivibrator, which drives a decade counter (IC2). The decade counter is set to count a sequence of four by connecting pin #10 to pin #15, although any sequence count in the range of 2-10 can be configured by selecting the appropriate pin connections. Additionally, LEDs, transistors, and their corresponding base-limiting resistors must be included or omitted as necessary. R1 serves as a variable resistor (trimmer) to adjust the speed of the LEDs. SW1 is a change-over switch, typically found in motorcycles, with positions for left, right, and a center-off position. D1, D3, D5, and D7 represent the left-turn LEDs, while D2, D4, D6, and D8 represent the right-turn LEDs. The circuit includes the following components: IC1 (7555 or TS555CN or TLC555CP CMOS Timer IC), IC2 (4017 Decade counter with 10 decoded outputs), SW1 (Vehicle Turn Lights switch), and a 12V vehicle battery.

The design incorporates a well-established circuit topology for a power amplifier, utilizing a single-rail supply of approximately 60V and capacitor coupling for the speakers. This configuration offers simplicity in circuitry, even for relatively high power outputs, and provides a degree of loudspeaker protection through capacitor C8. This capacitor prevents voltage supply from reaching the loudspeakers in the event of output transistor failure. The preamplifier operates on the same 60V rails as the power amplifier, facilitating the implementation of a two-transistor gain block capable of delivering around 20V RMS output, which results in high input overload capability.

Component specifications include:
- R11, R12, R47: 4W wirewound resistors
- C1, C2, C4, C5: 47 µF 63V electrolytic capacitors
- C3: 100 µF 25V electrolytic capacitor
- C6: 33pF 63V ceramic capacitor
- C7: 1000 µF 50V electrolytic capacitor
- C8: 2200 µF 63V electrolytic capacitor (minimum suggested value; a 3300 µF capacitor or two 2200 µF capacitors in parallel is recommended)
- D1: LED of any type and color
- Q3: MJ11016 120V 30A NPN Darlington transistor
- Q4: MJ11015 120V 30A PNP Darlington transistor
- SW1: SPST mains switch
- C1, C4, C8, C9, C10: 10 µF 63V electrolytic capacitors
- C2: 47 µF 63V electrolytic capacitor
- C3: 47pF 63V ceramic capacitor
- C5: 220nF 63V polyester capacitor
- C6: 470nF 63V polyester capacitor
- C7: 100nF 63V polyester capacitor
- C11: 220 µF 63V electrolytic capacitor
- Q1, Q3: BC546 65V 100mA NPN transistors
- Q2: BC556 65V 100mA PNP transistor
- J1, J2: 6.3mm mono jack sockets

Performance specifications include:
- Sensitivity: 70mV input for 40W output at 8 Ohms; 63mV input for 60W output at 4 Ohms
- Frequency response: 50Hz to 20kHz (-0.5dB); -1.5dB at 40Hz; -3.5dB at 30Hz
- Total harmonic distortion at 1kHz and 8 Ohm load: Below 0.1% up to 10W; 0.2% at 30W
- Total harmonic distortion at 10kHz and 8 Ohm load: Below 0.15% up to 10W; 0.3% at 30W
- Total harmonic distortion at 1kHz and 4 Ohm load: Below 0.18% up to 10W; 0.4% at 60W
- Total harmonic distortion at 10kHz and 4 Ohm load: Below 0.3% up to 10W; 0.6% at 60W

Bass control settings include:
- Fully clockwise: +13.7dB at 100Hz; -23dB at 10kHz
- Center position: -4.5dB at 100Hz
- Fully counterclockwise: -12.5dB at 100Hz; +0.7dB at 1kHz and 10kHz

The low-cut switch provides attenuation of:
- -1.5dB at 300Hz
- -2.5dB at 200Hz
- -4.4dB at 100Hz
- -10dB at 50Hz

It is essential to ensure that the sensing transistor (Q2) is in close thermal contact with the output transistors when using Darlington transistors as output devices. A TO-126 case transistor type is recommended for this purpose. Additionally, the transformer (T1) can be a 24 + 24V or 25 + 25V type (i.e., 48V or 50V center-tapped), with the center-tap left unconnected.This device was designed on request and allows sequential operation of four Leds either to left or right direction, obtained by means of a 7555 CMos timer IC (IC1) wired as an astable multivibrator driving a Decade counter (IC2). This IC is set to count a sequence of four by connection of pin #10 to pin #15, but any sequence count in the 2-10 rang

e can be set by choosing the appropriate pin connection. Obviously, LEDs, Transistors and their respective Base-limiting resistors must also be added or omitted accordingly. R1 is a variable resistor (Trimmer), used to set the desired speed of the LEDs. SW1 is a change-over switch that should already exist in your motorcycle, having a center-off position and Turn-left and Turn-right positions.

D1, D3, D5 and D7 are the Turn-left LEDs; D2, D4, D6 and D8 are the Turn-right LEDs. IC1_7555 or TS555CN or TLC555CP CMos Timer IC IC2_4017 Decade counter with 10 decoded outputs IC SW1_Vehicle Turn Lights switch (See Comments) Battery_12V Vehicle battery This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively high power outputs, and a certain built-in degree of loudspeaker protection, due to capacitor C8, preventing the voltage supply to be conveyed into loudspeakers in case of output transistors` failure.

The preamp is powered by the same 60V rails as the power amplifier, allowing to implement a two-transistors gain-block capable of delivering about 20V RMS output. This provides a very high input overload capability. R11, R12_R47 4W Wirewound Resistors C1, C2, C4, C5_47 µF 63V Electrolytic Capacitors C3_100 µF 25V Electrolytic Capacitor C6_33pF 63V Ceramic Capacitor C7_1000 µF 50V Electrolytic Capacitor C8_2200 µF 63V Electrolytic Capacitor (See Notes) D1_LED Any type and color Q3_MJ11016 120V 30A NPN Darlington Transistor (See Notes) Q4_MJ11015 120V 30A PNP Darlington Transistor (See Notes) SW1_SPST Mains switch C1, C4, C8, C9, C10_10 µF 63V Electrolytic Capacitors C2_47 µF 63V Electrolytic Capacitor C3_47pF 63V Ceramic Capacitor C5_220nF 63V Polyester Capacitor C6_470nF 63V Polyester Capacitor C7_100nF 63V Polyester Capacitor C11_220 µF 63V Electrolytic Capacitor Q1, Q3_BC546 65V 100mA NPN Transistors Q2_BC556 65V 100mA PNP Transistor J1, J2_6.

3mm. Mono Jack sockets Sensitivity: 70mV input for 40W 8 Ohm output 63mV input for 60W 4 Ohm output Frequency response: 50Hz to 20KHz -0. 5dB; -1. 5dB @ 40Hz; -3. 5dB @ 30Hz Total harmonic distortion @ 1KHz and 8 Ohm load: Below 0. 1% up to 10W; 0. 2% @ 30W Total harmonic distortion @ 10KHz and 8 Ohm load: Below 0. 15% up to 10W; 0. 3% @ 30W Total harmonic distortion @ 1KHz and 4 Ohm load: Below 0. 18% up to 10W; 0. 4% @ 60W Total harmonic distortion @ 10KHz and 4 Ohm load: Below 0. 3% up to 10W; 0. 6% @ 60W Bass control: Fully clockwise = +13. 7dB @ 100Hz; -23dB @ 10KHz Center position = -4. 5dB @ 100Hz Fully counterclockwise = -12. 5dB @ 100Hz; +0. 7dB @ 1KHz and 10KHz Low-cut switch: -1. 5dB @ 300Hz; -2. 5dB @ 200Hz; -4. 4dB @ 100Hz; -10dB @ 50Hz * The value listed for C8 is the minimum suggested value. A 3300 µF capacitor or two 2200 µF capacitors wired in parallel would be a better choice. * The Darlington transistor types listed could be too oversized for such a design. You can substitute them with MJ11014 (Q3) and MJ11013 (Q4) or TIP142 (Q3) and TIP147 (Q4). * T1 transformer can be also a 24 + 24V or 25 + 25V type (i. e. 48V or 50V center tapped). Obviously, the center-tap must be left unconnected. * SW1 switch inserts the Low-cut feature when open. * In all cases where Darlington transistors are used as the output devices it is essential that the sensing transistor (Q2) should be in as close thermal contact with the output transistors as possible.

Therefore a TO126-case transistor type