Design Improvements and Construction of an
Electric Fish Finder

By Jeffrey C. Lambert | Mentor: William G. R. Crampton

Tables

Table 1. Component list for Electric Fish Finder Mark II.

Component

Qty

Part number

Vendor

Circuit Board

 

 

 

Instrumentation amplifier: 8 pin IC

1

595-INA128PA

Mouser

Operational amplifier: 8 pin IC

1

NE5532PE4

TI

Operational amplifier: 8 pin IC

1

513-NJM#386BD

Mouser

IC Socket: 8 pin

3

276-1995

RadioShack

Capacitor (bipolar electrolytic) 470µF

1

P1170-ND

Digi-Key

Capacitor (bipolar electrolytic) 22µF

1

P1177-ND

Digi-Key

Capacitor (polypropylene) .22µF

2

P3224-ND

Digi-Key

Capacitor (polypropylene) .1µF

2

P3104-ND

Digi-Key

Capacitor (polypropylene) .047µF

1

PS1H473G-ND

Digi-Key

Capacitor (polypropylene) .022µF

2

P3917-ND

Digi-Key

Capacitor (polypropylene) .002µF

1

P3831-ND

Digi-Key

Capacitor (polyester film) 2.2nF

1

140-PM2A222K

Mouser

Capacitor (ceramic) 47pF

1

P4845-ND

Digi-Key

Resistor: 1MΩ 1/4W 1%

2

P1.00MCACT-ND

Digi-Key

Resistor: 270kΩ 1/4W 1%

1

P270KCACT-ND

Digi-Key

Resistor: 56kΩ 1/4W 1%

2

P56.0KCACT-ND

Digi-Key

Resistor: 180Ω 1/4W 1%

1

P180CACT-ND

Digi-Key

Resistor: 10Ω 1/4W 1%

1

10.0XBK-ND

Digi-Key

External to Board

 

 

 

8Ω 50mm round mylar cone speaker

1

GF0501M-ND

Digi-Key

3PDT Switch

1

506-MTE306E

Mouser

Aluminum L-Brackets

3

A21Z

Home Depot

3 Pin Watertight Connector, Female

1

EGG.2K.303.CLL

Delta Components

3 Pin Watertight Connector, Male

1

FGG.2k.303.CLAC55Z

Delta Components

Electronics Grade RTV Silicone

 

796-9845

Allied Electronics

Casing

 

 

 

Switch Boot Seal

1

506-B1440004

Mouser

Die-cast Alum. Watertight Enclosure

1

546-1590WP1BK

Mouser

#011 Silicone o-ring 25pk

1

ORS-011-25

Small Parts


Figures and Figure Legends

Figure 1. Schematic for Electric Fish Finder Mark II. Dashed lines refer to items located external to the printed circuit board.

Figure 2. Board layout for Electric Fish Finder Mark II. Magenta lines are the bottom layer traces and pads. Red lines indicate silk screen layer (not used in printed circuit board milling). Blue lines are top layer pads. The green outline is the board routing layer and indicates the shape of the board after milling.

Figure 3.Internal (A) and external (B) views of the Electric Fish Finder Mark II. 1. 3-pin electrode pair input. 2. Toggle switch. 3. Speaker. 4. Battery bay lined with foam, with battery-pack installed. 5. Neck-strap attachment swivels. 6. Printed circuit board (see Figure 1 for schematic). 7. Polyester-film type capacitor.

Figure 4. Jeffrey Lambert operating the EFF-mkII in a small rainforest stream near Jenaro Herrera, Loreto, in the Peruvian Amazon.

Figure 1. Schematic for Electric Fish Finder Mark II. Dashed lines refer to items located external to the printed circuit board.

Figure 2. Board layout for Electric Fish Finder Mark II. Magenta lines are the bottom layer traces and pads. Red lines indicate silk screen layer (not used in printed circuit board milling). Blue lines are top layer pads. The green outline is the board routing layer and indicates the shape of the board after milling.

Figure 3. Internal (A) and external (B) views of the Electric Fish Finder Mark II. 1. 3-pin electrode pair input. 2. Toggle switch. 3. Speaker. 4. Battery bay lined with foam, with battery-pack installed. 5. Neck-strap attachment swivels. 6. Printed circuit board (see Figure 1 for schematic). 7. Polyester-film type capacitor.

Figure 4. Jeffrey Lambert operating the EFF-mkII in a small rainforest stream near Jenaro Herrera, Loreto, in the Peruvian Amazon.