Benjamin W. Kidd - ENGR-162/12

A Presentation of Random Material in a Nonsensical Order

By Benjamin Kidd

Benjamin W. Kidd - ENGR-162/12

The DPDT Reversing Circuit

How do we switch polarity using a DPDT switch?

Benjamin W. Kidd - ENGR-162/12

The Knife Switch: A Simple DPDT

Benjamin W. Kidd - ENGR-162/12

DPDT Reversing Circuit

The Double Pole, Double Throw (DPDT) switch allows us to choose which direction a DC current flows into the load.

To LoadFrom DCPowerSource

Benjamin W. Kidd - ENGR-162/12

DPDT Reversing Circuit

Benjamin W. Kidd - ENGR-162/12

DPDT Reversing Circuit

Benjamin W. Kidd - ENGR-162/12

Diodes

Diode – A semiconductor device which acts as an electrical “one-way valve”. Diodes only pass current in one direction, namely from their cathode to their anode.

1N4002 Rectifier Diode

Benjamin W. Kidd - ENGR-162/12

Diode Ratings

What to look for: Type – Rectifier*, Small Signal, Zener PIV – Peak Inverse Voltage – The maximum

voltage at which the diode can be used (Remember, Peak NOT RMS for AC Circuits).

Maximum Average Forward Rectified Current – The continuous value amount of current that the diode can withstand.

Peak Forward Surge Current – The short term amount of current the diode can withstand.

*The Rectifier diode will probably be the most useful in this class

Benjamin W. Kidd - ENGR-162/12

Bridge Rectifier

Bridge Rectifier – A combination of four (4) rectifier diodes which rectify AC into DC. Bridge rectifiers can be made from four individual diodes or purchased as a package.

Benjamin W. Kidd - ENGR-162/12

AC Rectification

Half Wave Rectification – Passes only positive (or negative) half of AC Sine Wave

Full Wave Rectification – Changes AC into “pulsating” DC

RMSACRMSDC

peakACpeakDC

VV

VV

__

__

RMSACRMSDC

peakACpeakDC

VV

VV

_21

_

__

Benjamin W. Kidd - ENGR-162/12

AC/DC Application

Simple 2-Step Lamp Dimmer (Warning – Only Works on loads that work on both AC and DC!)

When switch is closed, the diode is shorted and circuit operates at full 120VAC RMS. When switch is open, current is forced to flow through the diode, and the load only see’s half of the sinusoidal voltage.

Benjamin W. Kidd - ENGR-162/12

DC Application

This circuit allows the control of two devices (loads) using only two wires with diodes located at the devices. Normally, this type of circuit would require three wires.

Benjamin W. Kidd - ENGR-162/12

Making the Connection

How to interconnect air systems reliably

Benjamin W. Kidd - ENGR-162/12

Making the Connection

How do I put an air connector on a hose?

Benjamin W. Kidd - ENGR-162/12

Knowing your Connectors

I use the ¼” NPT connection for my demonstrations in class.

Benjamin W. Kidd - ENGR-162/12

Making the Connection

Start with a Hose “Barb” connector, hose clamp, and hose end.

Benjamin W. Kidd - ENGR-162/12

Making the Connection

Put the clamp around the hose. Then, push the barb into the hose. (Important Note: Hose barb will not come out of hose after being pushed in – like a fishhook.)

Benjamin W. Kidd - ENGR-162/12

Making the Connection

Benjamin W. Kidd - ENGR-162/12

Tighten the hose clamp with a screw driver until screw is hard to turn.

Benjamin W. Kidd - ENGR-162/12

Making the Connection

Finished connection

Benjamin W. Kidd - ENGR-162/12

Connecting to Air

Prepare Connection with “Teflon” Tape. Wrap tape around threads leaving the first couple threads bare.

Benjamin W. Kidd - ENGR-162/12

Connecting to Air

Screw Connections together. Wrench-tight connections are the most leak-proof, but do not overtighten.

Benjamin W. Kidd - ENGR-162/12

Connecting to Air

Hmm…Gee Benjamin, this looks like this takes a lot of time.

Benjamin W. Kidd - ENGR-162/12

Using Quick Connectors

Quick Connectors allow rapid connection to air supplies, accessories, and hoses.

Female Connector Male Connectors

Benjamin W. Kidd - ENGR-162/12

Using Quick Connectors

Quick connectors attach to accessories and hoses using the normal “slow connect” connectors. Prepare the connection threads as before with Teflon tape.

Benjamin W. Kidd - ENGR-162/12

Using Quick Connectors

Wrench tighten to threaded connectors.

Benjamin W. Kidd - ENGR-162/12

Using Quick Connectors

Walla!

Benjamin W. Kidd - ENGR-162/12

Solenoid Controlled Pneumatics (Or Hydraulics)

Using the “SV-2” Solenoid-valve to control air flow.

Benjamin W. Kidd - ENGR-162/12

Solenoid Controlled Air

¾” “Garden Hose” ThreadTo 3/8” Barb All Electronics SV-2 Solenoid

Controlled Valve

Benjamin W. Kidd - ENGR-162/12

Solenoid Controlled Air

Connect ¾” to 3/8” Hose Barb connector to air hose. Screw connector to input port of solenoid valve. (Suggestion: Prepare input port threads of valve with Teflon tape.)

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Or…How to not have spaghetti in front of the stage.

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Control Position Grid Outlet

Benjamin W. Kidd - ENGR-162/12

Efficient Control Wiring

Benjamin W. Kidd - ENGR-162/12

Using Relays

Why did you bother mentioning these things, anyway?

Benjamin W. Kidd - ENGR-162/12

Simple Relay Circuit for 120VAC

Benjamin W. Kidd - ENGR-162/12

Simple Relay Circuit for 12VDC