amplifier

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STEP Skills Development and Competitions CONTEST AREA: Industrial Arts CONTEST PACKAGE 20-Watt Amplifier

YEAR LEVEL: All Year Levels

ASSESSMENT CRITERIA

Contestant/s

T PERCENTAGE

40%

Functionality

b. Submission of required documents for the contest.

4 hours

d. Briefing orientation of trainers with the contest administrator a

35%

Workmanship

day before the actual competition. e. Inspection and distribution of contest materials.

Organizer/s

a. 30w soldering iron with stand

PRELIMINARY ACTIVITIES

c. Ocular inspection of the contest venue.

DESCRIPTION

RESOURCES

PROCEDURE/SPECIFICATIONS

a. Contest registration of trainers and contestants.

TIME ALLOTMENT

Number of Participants: 1

T O O L S

b. long nose pliers c. diagonal cutter d. flat screw driver e. philips screw driver f. g. h. i.

electric drill reamer desoldering tool PCB holder

T

This contest piece is a low cost 20w Amplifier with Tone Control and Safety Microphone Mixer consisting of three circuits: the audio power amplifier, tone control and microphone mixer circuits mounted in a pre-board aluminum casing. Time The labels of the front and rear panels Management are designed from a computer and pronted in a piece of folder paper and is covered with a 2 1/4 inch scotch tape.

ILLUSTRATION

DURING 10%

administrator (10 minutes). b. Final instructions of trainers to their contestants (5 minutes). c. Inspection of contest materials, tools, and equipment.

10%

It can be used as sound system for cars or home. MP3 and CD players can be connected to its input and a microphone for sound mixing as in a videoke system. It can also be used as a sound system inside a classroom.

d. Other instructions (i.e. coaches)

a. Trainers shall serve as judges.

Communication Skills

5%

b.

All outputs shall be endorsed to the Secretariat by the Contest Administrator.

c. All endorsed outputs shall be displayed until the duration of the

skills com competition petition..

NOTES TOTAL

100%

ATTACHMENT(S) Analytic Scoring Rubrics/ Percentage Table/ Contact no. of PCB Supplier

FORM OF JUDGING Compatriot Judging

a. With regard to the provision of resources, the division and

regional organizers may opt to deviate. b. Coaches are allowed to observe the process within 3 meter

range. c. All diagrams shall be provided by the organizers.

a. Volt-Ohm Milliammeter (VOM)

3-Ampere Regulated Power Supply

a. Front and rear labels b. elmer's glue c. 1 roll 2-1/4" scotch tape

AFTER

Schematic Diagram, PCB Design with Components' Layout, Parts List of Kits EMPLOYABILITY OR BUSINESS OPPORTUNITY Sound System and BGM Installer

USE

a. Briefing of trainers and contestants with the contest

E Q U I P M E N T

M A T E R I A L S

d.

2 pairs alligator clips

a. 1 set 20W audio amplifier kit

with tone control and microphone mixer b. 4"X1-3/4"X8-5/8" aluminum

chassis c. 1 set 50W speaker system


PERFORMANCE SCORING RUBRICS FOR 20-WATT AMPLIFIER CRITERIA

A. FUNCTIONALITY

40%

B. WORKMANSHIP 35% Mounting and Placement of Components 10%

Soldering

10%

Circuit Wiring

10%

Mounting of Front and Rear Panels 5%

C. SAFETY WORK HABITS

10%

95 • Very clear sound, no hum, no distortion heard from the loudspeaker using MP3/MP4 player and microphone as line inputs for audio mixing with the volume control set at 50% and 70% volume ratio. • All components were properly mounted on PCB based on proper mounting of electric component*

PERFORMANCE LEVEL 90 85 • Normal sound output with • Normal sound output with minimum hum heard from the audible hum heard from the loudspeaker with or without loudspeaker with or without distortion. distortion.

80 • Weak sound output with or without hum or distortion.

• Less than 10% of components were not properly mounted

• 10% or more but less than 20% of components were not properly mounted

• 20% or more but less than 30% of components were not properly mounted

• All components and joints were properly soldered (no cold solder joints)

• Less than 10% of components and/or joints were not properly soldered

• Connecting wires were neatly laid out.

• One to three wires were damaged; connecting wires were neatly laid out.

• 10% or more but less than 15% of components and/or joints were not properly soldered • Four to six wires were damaged; connecting wires were neatly laid out

• 15% or more but less than 20% of components and/or joints were not properly soldered • Seven or more wires were damaged; connecting wires not neatly laid out

5

4

3

2

• Both front and rear panels were properly and accurately mounted without evidence of bubbles and scratch on the surface. • Work area was well kept. Tools and materials were properly arranged. No tool was damaged. No injury.

• Both front and rear panels were properly and accurately mounted but with presence of bubble/s and/or scratch on the surface.

• One of the panels was not properly mounted with evidence of bubble/s and/or scratch on the surface.

• Both panels were not properly mounted with the presence of bubble/s and or scratch in either front/rear panel

• Work area was partially kept. Some tools and materials were not properly arranged. One tool was damaged. No injury.

• Work area was adequately kept. Almost all tools and materials were not properly arranged. Two or more tools were damaged. No injury

• Tools and materials were left out in messy situation. Work area was left unclean. With minor injury (no presence of blood)


D. TIME MANAGEMENT

10%

E. COMMUNICATION SKILLS (3-5 minutes only)

5%

95 • The contestant was able to finish the output within three (3) hours or less • Able to clearly discuss/explain with confidence all of the following: a. process b. function of tools, materials and equipment c. cost of production d. employability e. business opportunity

90 • The contestant was able to finish the output within three (3) hours and 15 minutes. • Able to clearly discuss/explain with confidence 4 of the following: a. process b. function of tools, materials and equipment c. cost of production d. employability e. business opportunity

85 • The contestant was able to finish the output within three (3) hours and 30 minutes. • Able to clearly discuss/explain with confidence 3 of the following: a. process b. function of tools, materials and equipment c. cost of production d. employability e. business opportunity

80 • The contestant was able to finish the output within three (3) hours and 45 minutes. • Able to clearly discuss/explain with confidence 2 of the following: a. process b. function of tools, materials and equipment c. cost of production d. employability e. business opportunity

Front Panel of the Contest Piece MIC 1 Control VOLUME

BASS

MIC 2 Control

TREBLE MIC 1

MIC 2

POWER

20 WATTS AMPLIFIER WITH TONE CONTROLS AND AUDIO MIXER

STUDENT TECHNOLOGISTS AND ENTREPRENEURS OF THE PHILIPPINES


6-INPUT LINE MIXER

Parts List R1-R6 R7-R12 R13 R14 R15 R16 R17

= = = = = = =

22K 39K 100K 2.2K 6.8K 68? 1K

C1-C6 C7-C8

= =

10µF/16V 47µF/16V

Q1

=

C945

20 WATTS AUDIO AMPLIFIER


2-INPUT MICROPHONE AMPLIFIER

R1 - 47KΩ R2- 1MΩ R3- 1KΩ R4- 68Ω

R5- 4.7KΩ R6- 2.2MΩ R7- 22KΩ R8- 220Ω

C1- 10µF/16V C2- 47µF/16V C3- 47µF/16v C14- 47µF/16V

Q1 Q2

C945



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