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Gold Prospecting
Do It Yourself (DIY) Projects
Diy Variable voltage setup
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<blockquote data-quote="bicter" data-source="post: 469695" data-attributes="member: 1240"><p>Firey, </p><p>Please refer to my reply to Mr Magoo's post. </p><p>All the information you require is available in the application information linked previously. </p><p>A rough calculation shows that for 8.4V O/P, R/R2 should be around 1K/200R to ensure the required 7ma load current while for 5.9V, R1/R2 should be 750R/200R - This needs to be confirmed by testing. Value for 7.0V can also be calculated. I couldn't see anything in the data sheet regarding suitability or associated risk of switching resistors on the adj pin. There is a possibility that switching between the voltages could introduce a spike on the supply.</p><p></p><p>The design needs to consider the change in input voltage as the battery discharges. This will be determined by the battery chemistry and given the 8.4 I/P & 8.4V O/P required, it would be very easy for the regulator to drop out of regulation. Given the 1.5A current required at 8.4V this is a real possibility. </p><p></p><p>Battery protection will be required to prevent over discharge</p><p></p><p>Any circuit design you come up with would need to be thoroughly tested before connecting to the detector.</p></blockquote><p></p>
[QUOTE="bicter, post: 469695, member: 1240"] Firey, Please refer to my reply to Mr Magoo's post. All the information you require is available in the application information linked previously. A rough calculation shows that for 8.4V O/P, R/R2 should be around 1K/200R to ensure the required 7ma load current while for 5.9V, R1/R2 should be 750R/200R - This needs to be confirmed by testing. Value for 7.0V can also be calculated. I couldn't see anything in the data sheet regarding suitability or associated risk of switching resistors on the adj pin. There is a possibility that switching between the voltages could introduce a spike on the supply. The design needs to consider the change in input voltage as the battery discharges. This will be determined by the battery chemistry and given the 8.4 I/P & 8.4V O/P required, it would be very easy for the regulator to drop out of regulation. Given the 1.5A current required at 8.4V this is a real possibility. Battery protection will be required to prevent over discharge Any circuit design you come up with would need to be thoroughly tested before connecting to the detector. [/QUOTE]
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Gold Prospecting
Do It Yourself (DIY) Projects
Diy Variable voltage setup
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