ICL 7660 ALTERNATIVE

[daverave]

is there a pin for pin alternative to the icl 7660 which can take a supply voltage of between 16-18v ?????

[Qiaozhi]

is there a pin for pin alternative to the icl 7660 which can take a supply voltage of between 16-18v ?????

Not that I know of ..... but you could front-end it with a linear regulator that can handle the supply voltage.

[Altra]

Try to find a ICL7662 it can take 18 to 20 volts and has the same pin out as the 7660

[daverave]

Try to find a ICL7662 it can take 18 to 20 volts and has the same pin out as the 7660

thanks for that ive ordered a couple of the ICL7662.

[Qiaozhi]

Try to find a ICL7662 it can take 18 to 20 volts and has the same pin out as the 7660

Some manufacturers have this listed as an obsolete part. Also, if you visit the Farnell (Element 14) site, there is just one item listed for ICL7662 with a maximum voltage of 20V. This is from Maxim. There are only 20 in stock, and the price for a quantity of 1-2 is £88.08 each!!

[mickstv]

RS components still have them in stock for about $9 Australian

[daverave]

hi Qiaozhi
ive ordered a couple of ICL 7662 and i also found a 555 timer that can take 18v so very pleased now that i can use a higher coil voltage

[mickstv]

Some manufacturers have this listed as an obsolete part. Also, if you visit the Farnell (Element 14) site, there is just one item listed for ICL7662 with a maximum voltage of 20V. This is from Maxim. There are only 20 in stock, and the price for a quantity of 1-2 is £88.08 each!!

On the UK Element14 website they have listed ICL7662CPA+ Max 20v

Order Code 1228203
Availability: 7,337

• 790 in stock for next day delivery (Liege stock)
• 6,547 in stock for next day delivery (UK stock)

Cost £3.39



Link

http://uk.farnell.com/maxim-integrat...dip/dp/1228203

[Orbit]

http://www.mgelectronic.rs/ ..... (3 euros)

[daverave]

thanks for that mickstv.

[mickstv]

thanks for that mickstv.

Thats ok

18v so very pleased now that i can use a higher coil voltage

Why not leave the detector running on 12v and just make your TX pulse width, wider. You'll end up with the same result without all the extra expense.

[daverave]

im a bit vague concerning higher voltage...some say higher voltage gives a bit better proformance on lower conductive items like gold...i did see a slight improvement at around 17v but higher gave no real improvement...be interested in peoples views on this subject of voltage to coil.

[kt315]

lie. clear lie. higher voltage in coil (IN COIL) and (AND) the CURRENT you can get with MORE PULSE WIDTH only.

no another way.

ie if you have now 50us so if you go on 100us you get MORE TX power. but here is ONE moment...
throw out your 800mA*h batts in garbage basket. just cause you can not use SMALL RESERVE POWER batts
in HIGHT POWER EXPENSE UNIT.

for 1000us PULSE WIDTH unit you MUST use batt... look at this pic
and yes - you will get the depth. be ready also to use another power mos-fet... on another voltage
and another current.

[kt315]

http://www.geotech1.com/forums/showt...d-Theory/page4

Not too bad inside. The 22,000uF TX reservoir cap dominates the scene, with big heatsink for 2N5883 driver and PT7505 80A power transistor behind (no mosfet power then). Heat extraction fan at right end of HS. Relay is to charge capacitor up slowly in standby position on front panel switch (avoids melt down of switch with 50V supply). Pulse generator and sample generator board to the right, and RX to the left.

Eric.

pics inside the link

[kt315]