If this is for a PI detector (Minelab or other), you should use a switching regulator. Linear regulators are inefficient, and the Minelab PIs typically draw an amp or more.
The GP Extreme is a pulse induction (PI) detector. It draws about an amp when operating. If you use linear regulator, you will get about 60% of the battery life compared to a switching regulator. With a 12V battery, you will need a buck regulator.
Hero999, Yes the metal detector draws .8a to 1amp.would it work for this Pules induction detector, if so I need to have an out voltage of 6.7 constant. It will be hooked up with lead acid 12vdc 7anp hr, battery. vin 12vdc, vout 6.7vdc.
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All components as per the list on the page linked above except for:
Q1 needs to be fast, high gain (at least an Hfe of 50) and rated for 1A minimum (2A is better).
Zener is 7.5V
R2 is 820R
RZ is 3k3
L1 needs to be rated to 1.5A [/SIZE][/FONT]
Hero999, on your parts list it shows a capacitor as CS 47uf, but its not on the drawing??? the zener z1 couldn't find it, also the L1, and the Q1???? got on the net and nothing. do you know where I can get then. Thank You.