4841 electrical

Safety

Last week in theory class we went over safety procedures and work shop hazards. It is important that we follow the correct safety procedures for any jobs that we carryout in the workshop, failing to do so can put you and other works at risk of serious injuries or DEATH 


EXAMPLE

Never expose a battery to sparks or a naked flame because it could ignite the hydrogen around the battery after being driven or charged

Always wear overalls and safety glasses to protect your eyes and skin from the   h²so₄ sulfuric acid inside the battery 

Series circuit rules

·        The current is the same everywhere in the circuit.

Total resistance is the sum of resistive until added together.

Voltage drop across each component added up will equal to the batteries available voltage.

AVAILABLE VOLTAGE

We measured the available voltage on each component to determine if there is voltage flowing through each consumer.

VOLT DROP

We measured the voltage drop on each component we did this to see how much available voltage each light bulb is consuming

MEASURING AMPS

To measure amperage we first break the circuit and connect the multimeter in between the circuit to obtain a reading in 10ma (milli amps).

FINDING THE RISISTANCE

This is done by connecting the multimeter in OHMS to measure the amount of resistance on each component. V= I x R

parallel

Parallel circuits we measured the available voltage, volt drop, amperage and resistance also the watts. Each component on the circuit had their own voltage supply as to the series circuit which voltage is shared.

The brightness of each light bulb is equal with a 12v volt drop.

When we moved onto a compound circuit we noticed that the two light bulbs in series emitted less light and the bulb in series emitted more light  

Logic probes

Today in practical class we constructed logic probes to make the probe we needed.

·        Brass rod 150 mm long for proper conduction

·        Red LED

·        Green LED

·        Black wire 2 meters long

·        2 resistors 1k ohms

·        Red alligator clip 

·        Black alligator clip

·        100mm plastic tube 7mm

·        Shrink tubing black 2.4mm diameter/red 6.4mm diameter

Black – red LED

Red + green LED

When we connected the positive and negative lead to the 12v battery supply both green and red LEDs emitted light this means that the electricity is flowing through both positive and negative terminals.

 When we disconnected the positive terminal and connected the probe to the positive the red LED turned off and the green LED emitted more light this is because all the voltage is flowing through one LED and one resistor the electricity is finding the shortest path through the circuit.