Mini-Z Lights

How to install front, rear, and under car lights in a Kyosho Mini-Z car.

This page demonstrates how to install front, rear and under car lights in a Kyosho Mini-Z car.

For this example I modified a Kyosho Mini-Z AWD, VW Golf R32. The modification includes two white front LED’s, two red rear LED’s, and two bars with 4 blue LED’s each and a simple electronic circuit to keep the lights on without flickering or changing brightness.

The circuit is active while driving forward or backward and braking. There is an additional short delay (actual 3s) after the motor stopped and before lights turn off automatically. Delay time can be changed by values of R2 and C2. See schematic for calculation.

A simple NE555 timer working as monoflop is used to drive the LED’s lights by a power MOSFET. The 555 creates the delay and keeps the lights on independent of motor speed and direction.

Electronic circuit (Click for better resolution)

LED circuit (Click for better resolution)

Components placement

Layout

Parts required

Name	Value	Package
C1	10nF	0805
C2	10uF	0805
C3	100nF	0805
D1	1N4148	0805
D2	1N4148	0805
D3	1N4148	0805
IC1	NE555 SMD	SO8
IC2	SI4410BDY SMD	SO8
R1	10K	0603
R2	270K	0603
R2	10K	0603

The diodes 1N4148 should be in 0805 package if available, Mini-MELF will work as well but mounting is a bit tricky then.

Click images to enlarge

Soldering wires on cars PCB	Soldering ground wire	Size of circuits PCB
Left body conenction	Right body connection	Rear LED’s
Front LED installation	Right chassis connector	Left chassis connector
Complete PCB installation	Front LED’s	Right front LED
Front lights on	Front lights on	Rear lights
Rear lights on	Overview	Under car light LED bars
Under car light turned on	Side view	Side view in darkness
Close front view	Side view	Overview

Tricks:

• Do not cross polarity of the circuit, it will destroy the 555
• Remove batteries from the car while working on the electronic!
• Always use series resistors to limit the LED current, calculate like R=(Ubatt – Uled) / Iled
  I used 20Ohms for two parallel connected white LEDs, and 56Ohms for two in series connected red LED’s
  24Ohms for 4 blue LEDs in parallel on the under car light bars
• After LED installation use some black paint to cover the LEDs from inside the body to reduce flare light under the car. See image Overview, it’s without paint