HP 6654A Opt.J23 - Page 1
Forum section: electronics / repair

author: kjk24
author_rank: Regular Contributor
timestamp: September 21, 2024, 10:53:22 am
content: Hi,the Powersupply HP 6654A has Option J23 Label on the backside.Has someone more information for the Option J23 ?, i found this but its only a sellers information6654A-J23Output voltage: 0 to 60 V (0-80V opt.J23)Output current (40°C): 0 to 9 A (0-6A opt.J23)I repair it for a while now.The voltage is higher then expected and current is to low.I cant calibrate it with the standard eeprom setting becouse the calibration constants dose not fit to the values what the device produce during calibration.i changed the calibration eeprom settings to fit with the Voltage what the PS generate (~75V).like this i can calibrate the Voltage and overvoltage. But the current is strange, when i start the calibration the first current point is around 0.4A and the second point it shows UNR and the current is only 5.6A with a 0.11Ohm Resistor.i made the calibration Basic Programms to python and use a Agilent GPIB interface to reprogramm the eeprom Settings, i attatch it. (you should know what you do with the scripts !! have a look into it first !)has some one A unit and can readout the eeprom constants for me please ? i can assist how to doit.thanks a lot.greetings KK

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 21, 2024, 11:49:59 am
content: Hi KK,I went through a similar process with another Agilent power supply. Take a look at this thread:https://www.eevblog.com/forum/testgear/hp-6673a-power-supply-removing-option-j08/msg4607125/#msg4607125Look at the pdf file attached to that message. You will probably have to similar changes to the control board.I have a standard 6654A here. I could extract the EEPROM contents.Regards,Jay_Diddy_B

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 23, 2024, 02:45:01 am
content: kjk24I have read the EEPROM contents from a working HP6654A for you. I have formatted the data in the same format that is presented in the HP Service Manual:Code:Read from a working HP6654AReadOnly Eprom_data_6654 = New Decimal() {64.8304, 16.4637, 61.425, 0, 83, 0, 390.422, 137.804, 9.214, 0,99, 1, 10.5739, 75.75, 66, 0, 83, 255, 20, 10,6654, 60.819, 168.195, 403.354, 168.119, 1767, 6, 255, 0, 0,16, 6654, 0, 20, 180, 20, 180, 156, 37, 26,186, 15, 20, 0, 4}The initalization values from the HP Service ManualReadOnly Eprom_data_6x54 = New Decimal() {64, 16.35, 61.425, 0, 83, 0, 393, 127, 9.214, 0,99, 1, 10.43, 78.2, 66, 0, 83, 255, 20, 10,6654, 60.81, 168, 405.41, 168.18, 1768, 5, 255, 0, 0,16, 6554, 0, 20, 180, 20, 180, 156, 37, 26,186, 15, 20, 0, 4}I believe that you will need to change some resistors on the control board to remove the option. On the units that I remove the option, there was flux residue on the resistors that had been changed by HP.I hope that this helps.Regards,Jay_Diddy_B

author: kjk24
author_rank: Regular Contributor
timestamp: September 23, 2024, 04:42:35 am
content: Thank you verry much for the data, i will compare it withmy settings . I have the eeprom layout documented , it is not finished but i will post it maybe you have information too for it. The resin info dose not help anymore 👍 because i replaced a lot of components in the unit. I can now cal the voltage and overvolt to 80volt the current cal still fail the second cc cal is unr and the current is 5.4amp. i post more later.eeprom Data meanhex/dec0x02 2= ? the knob step fine/corse is changed but the Displayed value is changed too , 5=0.2, 1000=0.001, 500=0.002, 200=0.005, 100=0.01 , its overwritten during CV calibration, 48.56580x06 6= ? 15.84460x0A 10= Volt Max 82.00000x1C 28= Current Max 6.00x20 32= 00x14 20= ? the knob step fine/corse is changed but the Displayed value is changed too , 5=0.2, 1000=0.001, 500=0.002, 200=0.005, 100=0.01 , its overwritten during CC calibration0x18 24= DAC out in CC Mode ?0x26 38= OVCal constants 10x2A 42= OVCal constants 20x2E 46= Overvolt Max 82.50000x32 50= 00x40 64= Password 66540xA5 165= HPIB ADDRESS 50x9E 185= Model Number 66540x44 68= LCD CV constants 10x48 72= LCD CV constants 20x4c 76= LCD CC constants 10x50 80= LCD CC constants 2higher constants lower LCD Voltage are shown,the allowed setting for the VCal const2 wars -/+ ~10Vthe eeprom attatched picture are the constants (Little-Endian) marked with Sizes from the Service Manualbest Regards,kk

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 24, 2024, 01:56:59 am
content: kjk24,I think this part of software in the Service Manual gives the locations of the calibration data:Code:2380 Fact_cal_sour: ! Address of factory calibration data source2390 DATA 2,6,68,72,20,24,76,80,1502400 !2410 Fact_cal_dest: ! Address of factory calibration data destination2420 DATA 84,88,92,96,100,104,108,112,1162430 !2440 Fact_cal_len: ! Length of factory calibration data2450 DATA 4,4,4,4,4,4,4,4,22460 !2470 RESTORE Fact_cal_sour2480 F0R I=1 TO 92490 READ Cal_sour_addr(I)2500 NEXT I2510 !2520 RESTORE Fact_cal_dest2530 FOR I=1 T0 9These locations are not changed by HP's program84,88,92,96,100,104,108,112,116The Source locations are:2,6,68,72,20,24,76,80,150ReadOnly Eprom_data_6654 = New Decimal() {64.8304, 16.4637, 61.425, 0, 83, 0,390.422, 137.804,9.214, 0,99, 1, 10.5739, 75.75, 66, 0, 83, 255, 20, 10,6654,60.819, 168.195,403.354, 168.119,1767, 6, 255, 0, 0,16, 6654, 0, 20, 180, 20, 180, 156, 37, 26,186, 15, 20, 0, 4}I have indicated the calibration data in red.64.8304, 16.4637, 61.425, 0, 83, 0, 390.422, 137.804, 9.214, 0,99, 1, 10.5739, 75.75, 66, 0, 83, 255, 20, 10,6654, 60.819, 168.195, 403.354, 168.119, 1767,6,255, 0, 0,16,6654, 0, 20, 180, 20, 180, 156, 37, 26,186, 15, 20, 0, 4}HPIB ADDRESS IS 6Password 6654Model Number 6654Regards,Jay_Diddy_B

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 24, 2024, 02:47:47 am
content: kjk24,Have you checked the part number on the main power transformer to make that the J23 version uses the standard power transformer?The part number for the power transformer should be:65/6654A9100-4846Power TransformerThe currents sense amplifier is shown like this in the schematics:But if you check the values of the resistors for the 6654A model in the parts list you get this:With these components values the voltage on test point 28, the output of U605, is 10V when there is 9A flowing in the current shunt.I suggest that you check the component values in this part of the circuit.Regards,Jay_Diddy_B

author: kjk24
author_rank: Regular Contributor
timestamp: September 24, 2024, 06:22:03 pm
content: Hi Jay_Diddy_B,thank you for the information i updated the results in eeprom Map with your infowith your licence hopefulymy procedure for Vcalwithout setting the Voltages first i wars not able to cal1. write to Overvolt Register a verry high value what the unit cant reach Register (0x2E/46) = 88.0 V (for my unit)2. write to 0x0A/10 = 82.0 V (Volt Max User input)3. Calibrate Vcal1 and then Vcal2 and save it4. write to Register (0x2E/46) = 82.5 (for my unit)5. Cal Overvoltage6. disable calthis works for me without errors with option J23I looked for the Transformator, its a 9100-5059The Resistor values are the following:20mR shuntR646 = 80kR648= 0.947kR662= 56.3RR647= 0.894kR659= 56.5RR660= 80kif you could add this to your simulation would be wonderfulhttps://tinyurl.com/2bmkh7fo

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 25, 2024, 12:47:14 am
content: kjk24,I am not sure if you can convert this unit from j23 to the standard model. The j23 option has a different part number on the main transformer than the standard model.The standard model started with transformer part number 9100-4846. The Keysight website has this replaced By 5065-6957.This is the mains transformer for the 6554A and 6654A.I am unable to find any information on the transformer 9100-5059.I suspect that this is a higher-voltage, lower-current version of the transformer that would be required for the J23 option.Regards,Jay_Diddy_B

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: September 26, 2024, 01:02:53 pm
content: This may help:Code:Address,6671A,6672A,6673A,6673A J08,,,,,,2,459,181,103.46,91,cal_data6,70,75.038,80.8,82,Cal_data10,8.19,20.475,35.8,41,Max Voltage14,0,0,0,0,18,83,99,99,99,19,0,0,0,0,20,14.561,31,60.3,74.6,cal_data24,39.45,88.988,90.2,92,cal_data28,225.23,102.375,61.5,51.5,Maximum Current32,0,0,0,0,36,98,82,82,82,37,3,1,1,1,38,88.65,35.416,20.4,18.68,42,0,18,19.25,20,46,10,24,42,48,50,0,0,0,0,54,83,99,99,99,55,225,255,255,255,56,20,20,20,20,57,10,10,10,10,64,6671,6672,6673,6673,Password68,455,161,97.2,85,cal_data72,168,500,501,500,cal_data76,13.7,31,53.14,65,cal_data80,163,500,502,500,cal_data150,1768,1768,1775,1768,cal_data152,5,5,5,5,HPIB Address153,225,255,255,255,154,0,0,0,0,155,0,0,0,0,156,1296,1296,1296,3344,158,6671,6672,6673,6673,Model160,0,0,0,8,Option162,20,20,20,20,163,180,180,180,180,164,20,20,20,20,165,180,180,175,175,166,175,175,175,175,167,33,33,33,33,168,98,98,98,98,169,115,115,115,115,170,30,30,30,30,171,20,20,20,20,172,1,1,1,1,174,58,58,58,58,Open this in a spreadsheet and you will see:I don't have an HP6654 J23, but you can see how the EEPROM contents change between other similar models.Regards,Jay_Diddy_B