# LD3 dynamic light - IPRS Baneasa - Prospect 9117

#### What does the project present?

In the following we present a simple dynamic light scheme, recommended for beginner builders. The assembly is able to generate multiple dynamic variants such as: sequential operation (direct and inverse) and a pseudo-random one.

The scheme consists of an oscillator built with the integrated circuit CI1 CBD 404 (SN74F04N) which contains 6 inverters and has a low working frequency set by C1 and R1.

#### How does the assembly work?

If you want to change the frequency, you can insert instead of the resistor R1 a pontentiometer P = 1 KOhm inserted with a resistance of R = 150 Ohm. This resistance avoids blocking the oscillator at high operating frequencies. The approximate frequency is F = 1/3 RC.

The oscillation thus obtained is applied on the tactile inputs of the two displacement registers (CI3, CI4) which are connected in series. These two registers move the sequence from A to D2.

To obtain several combinations, a logic block consisting of the circuit was introduced CI2 CDB 400 (SN7400 / 74LS00), which realizes a succession of combinations, with the help of the switch K placed in position S.

The operating principle of the game is based on notifying the information on the last bit (the last two) and transmitting it on the serial input. Depending on the position of the switch, the information can be circulated directly, inverted or in the form of a pseudorandom sequence. If you want to repeat a certain combination, move the switch to the Vcc position.

Mounting power supply it is made from a well filtered and stabilized voltage source capable of providing a minimum current of 300 mA.

#### List of required components (with recent equivalents):

• IC 1 - integrated circuit CDB 404 or SN74F04N
• CI 2 - CDB 400 or SN7400 / 74LS00 integrated circuit
• IC 3-4 - integrated circuits CDB 495 or SN 7495 / 74LS95B
• R1 - 560 Ohm resistor (minimum 0.25W)
• R2-R9 - resistors 470 - 680 Ohm (minimum 0.25W)
• C1 - 220 uF / 16V capacitor
• D1-D8 - LEDs
• Switch type KTL 22 or rotary switch 6 positions CK1060
• 5V / minimum power supply 300 mA
• Printed wiring or breadboard test board