mosfet replacement for tip120?

So a 5 V drive? You could look up logic level mosfets on digikey. Is there a diode across the solenoid drive? (for inductance)

George H.

The TIP120 is a medium power darlington NPN rated for 60 volts. It has the reverse diode built in.

Why not just buy the tip 120 ? They are only from about $ .50 to $ .75 from several big dealers.

Even ebay has what you want for less than $ 6 for 5 of them including shipping. The larges cost is the $ 4 for shipping That the arcade game machine is mentione in.

Huh, thanks. I knew it is a darlington, I didn't know about the diode. Still you might want to add a diode on the coil... I'm a belt and suspenders type.

George H.

I don't like using darlingtons for power drivers. A momentary shorted load, and the darlington blows up from too much current. This article should provide some detail: I can't offer any specific recommendations without some clue as to the processor output voltage and current capabilities, the solenoid specs, and the operating voltage.

I use a TIP120 in a lamp heater (Rubidium lamp). It's nailed right to the lamp housing (besides a power resistor that shares the work.) Works great. It must be a fairly robust piece of silicon, 'cause I've used it to raise the lamp temperature to 150 C and let it run for days like that. (typical operation temp is 120 C.. for years.)

George H.

s driven right off the processor leg, no pre -driver transistor. didnt even think that was possible, maybe that why it blew. is there a mosfet i can replace the tip120 with?

I wouldn't worry about using a Darlington as a coil driver. Arcade games a re generally quite robust (the monitors generally the weakest point) and th ey've been using them for years with no issues. They used to use relays or even high current leaf switches to drive coils but relays and switches hav e a finite life.

Well, actually. no, arcade games (pinball games) using TIPs and other BJTs have a nasty habit of failing and cooking their coils and the circuit board. Many of us in the trade are getting around to finally ripping out all these dinosaurs and replacing them with modern devices. It has taken me far too long to realize I am not doing customers a favour by leaving old tech in their games. As the link Jeff provided you get up to 4VDC drop across the BJT so a MOSFET with less than 1V drop will give you more pop too!

Most of the aftermarket replacement boards are using MOSFETs except for a few holdouts whose quality suffers in other areas too.

Still for the OP who has a CHEXX game the TIP120 should last forever, it has at most a 1A draw, and we have never replaced one in the 30 odd years I've been servicing CHEXX boards.

John :-#)#

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is driven right off the processor leg, no pre -driver transistor. didnt e ven think that was possible, maybe that why it blew. is there a mosfet i can replace the tip120 with?

es are generally quite robust (the monitors generally the weakest point) an d they've been using them for years with no issues. They used to use relay s or even high current leaf switches to drive coils but relays and switches have a finite life.

From about 1982 until he sold the company about 8 years ago, I did all the electrical work for a vendor who became a very good friend of mine. The va st majority of the work I did for him were monitor failures. Most of the e lectrical work he did was swapping out game boards, converting cabinets and replacing hard drives. He would shop the pinballs as they were rotated or were pulled for failures and if there was a problem beyond lamps, rubbers, solenoids etc. I'd get the board.

I rarely saw shorted Darlingtons. I agree that MosFets are better suited t o switching, but other than upgrading the ratings of the replacements, we n ever felt the need to do wholesale replacements of Darlingtons that would m ost likely last the life of the game. It was far easier to deal with them i ndividually.

I hear what you are saying, but when you run into boards where most of the transistors show signs of overheating the PCB (Atari lamp driver Aux board for example) then one considers replacing the old BJTs with more modern devices to improve the expected lifespan.

John :-#)#

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ames are generally quite robust (the monitors generally the weakest point) and they've been using them for years with no issues. They used to use rel ays or even high current leaf switches to drive coils but relays and switch es have a finite life.

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the electrical work for a vendor who became a very good friend of mine. T he vast majority of the work I did for him were monitor failures. Most of the electrical work he did was swapping out game boards, converting cabinet s and replacing hard drives. He would shop the pinballs as they were rotate d or were pulled for failures and if there was a problem beyond lamps, rubb ers, solenoids etc. I'd get the board.

ed to switching, but other than upgrading the ratings of the replacements, we never felt the need to do wholesale replacements of Darlingtons that wou ld most likely last the life of the game. It was far easier to deal with th em individually.

Wow, that triggered an old memory. I do remember adding heatsinks to all t he TO-202 free standing driver transistors on certain boards many years ago , but don't recall which one. Stern pin maybe?

But I suppose changing all the transistors over to mosfets in 30 year old g ames in 2017 is analogous to doing wholesale capacitor replacement in old r adios. I guess age catches up to everything.