Parts Substitutions for HM 4.3


 

Wesley Talbot

New member
I ordered the HM 4.3 thermocouple PCB set and now I'm on the hunt for components. This is obviously difficult given current shortages, but I'm trying to do what I can. I'm also trying to buy from a minimum number of suppliers (primarily Mouser) to reduce shipping costs, so that adds some difficulty. I was hoping to get a bit of feedback on the following substitutions:

-Swap all 1/4W carbon film resistors with 1/4W 1% tolerance metal film resistors (I have these on hand but wasn't sure if there is an issue doing that in this application)
-Swap caps C4, C5, C6, and C12 standard parts all with Nichicon UHE1E101MED. I recall reading a 100u/25v cap could be used in all 4 of those places and this seems to be a good performing option with low ESR, plus it's in stock.
-Swap resonator Y1 standard part with CSTLS16M0X55-A0 - I think I read these have been used before?
-Swap MOSFET Q3 with IRFU9024NPBF - this is where things get iffy for me because MOSFETs have a bunch of specs and I'm not sure what's critical in this application.
-Swap DC Converter IC1 with Murata OKI-78SR-5/1.5-W36-C. Appears to be identical, but I'll need to re-solder a straight 3-pin header in.
-Swap power jack J9 with 694106301002 - dimensions look near identical so I don't anticipate any problems with this.
-Swap buttons S1, S2, S3, S4 with 430476085716 - again very similar if not identical to original spec parts (button is actually black, unlike the Mouser pic shows)

All of the above and most of the other required parts can come from Mouser, but I've still got to get my hands on an ATMEGA328P-PU. Appears that Jameco has that, so I'll probably have to order from there. Raspberry Pi's are also unobtanium at this point unless you want to pay a scalper, but I managed to pick up a lightly used RPi Zero W locally for a reasonable price, and all initial checks seem good on it.

Any opinions are much appreciated on the above substitutions! The MOSFET is what concerns me the most, so I'll go to another supplier for that if absolutely critical.

Thanks for the help!
 

Wesley Talbot

New member
OK, found out Mouser does in fact have the correct resonator and power buttons in stock, so I'm set there. The Wiki links to those went to an OOS component, but If I searched for the manufacturer p/n then there were some other options depending on packaging. I also came across another thread where it said metal film resistors are fine, so no issue there either.

My main concern now is that MOSFET!
 
Last edited:

Wesley Talbot

New member
I decided to go ahead and place an order before certain things went out of stock. I'll circle back on any other components if I need them. I bought the ATmega328P from Jameco which kind of drove the cost up ($14+ shipping). Here are the components I bought from Mouser (I did order extras of most of the less expensive components, but this is the base list):

Mfr. #ManufacturerDescriptionOrder Qty.
MF1/4DCT52R1001FKOA SpeerMetal Film Resistors - Through Hole 1Kohms 1% 100PPM
4​
MF1/4DCT52R2201FKOA SpeerMetal Film Resistors - Through Hole 1/4W 2.2K ohm 1% 2.2K OHM 1%
1​
MF1/4DCT52R1002FKOA SpeerMetal Film Resistors - Through Hole 10Kohms 1% 100PPM
5​
MF1/4DCT52R2202FKOA SpeerMetal Film Resistors - Through Hole 1/4W 22K ohm 1%
1​
MF1/4DCT52R6802FKOA SpeerMetal Film Resistors - Through Hole 1/4 WATT 68K OHM 1%
1​
MF1/4DCT52R1003FKOA SpeerMetal Film Resistors - Through Hole 100Kohms 1% 100PPM
5​
K104K15X7RF53L2VishayMultilayer Ceramic Capacitors MLCC - Leaded 0.1uF 50volts 10% X7R 2.5mm LS
8​
UHE1E101MED1TDNichiconAluminum Electrolytic Capacitors - Radial Leaded 100UF 25V 105c PET
4​
CSTLS16M0X53Z-A0MurataResonators 16.0 MHZ
1​
1N5819STMicroelectronicsSchottky Diodes & Rectifiers Vr/40V Io/1A AMMO
2​
AIUR-02H-221KABRACONFixed Inductors 20 UH 10%
1​
PS1240P02BTTDKPiezo Buzzers & Audio Indicators Round 12.2mmx6.5mm 4kHz Vin=3V
1​
BS170onsemiMOSFET FET 60V 5.0 MOHM TO92
4​
IRFU9024NPBFInfineonMOSFET MOSFT P-Ch -55V -11A 175mOhm 12.7nC
1​
OKI-78SR-5/1.5-W36-CMurataNon-Isolated DC/DC Converters 7.5W 12VIN 5VOUT 1.5A DC/DC
1​
68001-203HLFFCI / AmphenolHeaders & Wire Housings 3POS HDR 15AU
1​
MCP1700-3302E/TOMicrochipLDO Voltage Regulators 250mA LDO 2%
1​
MJ1-2503ACUI DevicesPhone Connectors Audio Jacks
4​
694106301002Wurth ElektronikDC Power Connectors WR-DC PwrJk CtrPnTHT Right Angled
1​
RJHSE-5080AmphenolModular Connectors / Ethernet Connectors R/A RJ45 NONSHIELDED 8 CONT NO LEDS
1​
1-2199298-9TE ConnectivityIC & Component Sockets 28P DIP SKT 300 CL LADDER
1​
M20-7831346HarwinHeaders & Wire Housings 13+13 DIL VERTICAL SOCKET TIN
1​
MF1/4DCT52R2200FKOA SpeerMetal Film Resistors - Through Hole 1/4W 220 ohm 1%
2​
MF1/4DCT52R1201FKOA SpeerMetal Film Resistors - Through Hole 1/4W 1.2K ohm 1%
1​
MF1/4DCT52R1801FKOA SpeerMetal Film Resistors - Through Hole 1/4W 1.8K ohm 1%
1​
MF1/4DCT52R3901FKOA SpeerMetal Film Resistors - Through Hole 1/4 WATT 3.9K OHM 1%
1​
MF1/4DCT52R8201FKOA SpeerMetal Film Resistors - Through Hole 1/4W 8.2K ohm 1%
1​
T73YE103KT20VishayTrimmer Resistors - Through Hole 1/4"SQ V/ADJ 10K
1​
SN74HC595NTexas InstrumentsCounter Shift Registers Tri-State 8-Bit
1​
68001-236HLFFCI / AmphenolHeaders & Wire Housings 36P HDR
1​
M20-7820542HarwinHeaders & Wire Housings 5 PIN SIL VERTICAL SOCKET GOLD+TIN
2​
PTS125SM852LFSC&K SwitchesTactile Switches 50mA 12VDC 180gF 8.5mm Act Tact
4​
WP710A10SRD/FKingbrightStandard LEDs - Through Hole Red 460mcd 640nm 40 deg Diffused
1​
WP710A10SGDKingbrightStandard LEDs - Through Hole Grn 40mcd 568nm 40 deg Diffused
1​
WP710A10SYDKingbrightStandard LEDs - Through Hole Yel 1100mcd 590nm 40 deg Diffused
1​
NHD-0216K1Z-FSW-FBW-LNewhaven DisplayLCD Character Display Modules & Accessories FSTN (+) Transfl 80.0 x 36.0
1​
BFB0512VHD-F00Delta ElectronicsBlowers & Centrifugal Fans Blower, 50x20mm, 12VDC, Ball, 3-Lead Wires, Lock Rotor Sensor, Tachometer
1​
 

 

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