Altium Designer: Useful Shortcuts for Component Placement

  - Rotate counterclockwise by 90 degrees while moving an object : SPACEBAR
  - Align selected objects by top edges  : SHIFT + CTRL + T
  - Distribute selected objects equally in horizontal plane : SHIFT + CTRL + H
  - Align selected objects by left edges : SHIFT + CTRL + L
  - Align selected objects by right edges : SHIFT + CTRL + R
  - Distribute selected objects equally in vertical plane : SHIFT + CTRL + V
  - Align selected objects to grid : SHIFT + CTRL + D
  - Align selected objects by bottom edges : SHIFT + CTRL + B

Altium Designer : Pcb Panelization

On the Place tab, Select Embedded Board Array/ Panelize. Click anywhere in the PCB area. Under Properties menu, select your PCB and set desired Column margin and Row spacing.

Altium Designer : Creating Board Outline From Mechanical Outline and Making Cutout Holes

Select Mechanical Outline. Under Properties menu, Change Mechanical outline layer to user defined board outline layer.
To create custom board shape, select board outline that has been created. On the Design Tab, in the board shape, select Define from selected Objects.
To create a cutout hole, select the desired outline. On the Tool Tab, in the Convert, select Create Boardcutout from selected primitives.

Altium Designer : Moving Design Origin to User's Preferred Location

On the Edit tap, in the Origin,  choose Set.

Altium Designer, Shortcuts for Viewing, Changing Grid and Snap Setting

Toggle measurement Unit : Q
Accessing Grid menu : G
Changing snap setting : SHIFT + E
Switching 2D and 3 D View : 2 & 3
Fit all objects into view : CTRL + PAGE DOWN
Zoom in around cursor (zooms around cursor, position the cursor first) : CTRL + Mouse-wheel up (or PAGE UP)
Zoom out : CTRL + Mouse-wheel down (or PAGE DOWN)

AAA Battery Protection with Wrong Polarity LED Indicator

This simple circuit will protect AA or AAA battery from wrong polarity connection to your device. If the battery is connected in opposite way, D1 will conduct and PTC Fuse will break the circuit. Wrong polarity indicator, LED 1 will be turned on at the same time.