I might be stupid but what is LS1:TV3??

Hi John

NO ... on the schematic, T1 is the transistor
the device you are worried about is labelled correctly at LS1 TV3

its a buzzer ... maybe piezo

Dave

 

On that schematic, each part has 2 tags.

One is a logical abbreviation, T1 is the first transistor. LS1 is the first "loud speaker", R2 is the second resistor, etc..

The second tag is the part number, or more detailed information. So T1 is also labelled BC547 (and presumably you'll see BC547 written on the transistor). Likewise you'll find the IC has PIC12C508A (or similar) written on it. The resistors have colour codes which indicate the resistance, so the resistors that can be used for R1 thru R4 will all have the same colour code representing 470 ohms.

This is all pretty standard.

Sometimes you might see only the first tag on the schematic (so just R4, LD2, IC1, LS1, SW3, etc.) and a separate list of these with their component values etc listed beside them. This list is very useful where you have to go out and purchase the components. It essentially works as your shopping list. For more complex circuits it also avoids the need to continually refer to the schematic to populate the board.

In this example, the schematic is provided (perhaps) for completeness. The step by step instructions allow you to build it without needing to understand how to read a schematic or even how to identify parts (although that's what I guess it thinks you should be learning).