comparison: content/LPD422FM.rst
content/LPD422FM.rst
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| 7 :Tags: test equipment, PSU | 7 :Tags: test equipment, PSU |
| 8 | 8 |
| 9 This post is a quick presentation and teardown of a small bench power | 9 This post is a quick presentation and teardown of a small bench power |
| 10 supply I bought on ebay a few weeks ago for something like 40€. | 10 supply I bought on ebay a few weeks ago for something like 40€. |
| 11 | 11 |
| 12 .. image:: {filename}/images/lambda/lpd422fm_overall.jpg | 12 .. image:: {static}/images/lambda/lpd422fm_overall.jpg |
| 13 :alt: The Lambda LPD 422 FM dual regulated power supply. | 13 :alt: The Lambda LPD 422 FM dual regulated power supply. |
| 14 | 14 |
| 15 It's an old unit, not sure it's exact age, but the components inside | 15 It's an old unit, not sure it's exact age, but the components inside |
| 16 the unit seem to have date codes around 1971/1972. So my unit is | 16 the unit seem to have date codes around 1971/1972. So my unit is |
| 17 probably from the late 1972 (older than me!). This series of power | 17 probably from the late 1972 (older than me!). This series of power |
| 31 | 31 |
| 32 | 32 |
| 33 It seems to be "remote programmable", and have remote sensor entries | 33 It seems to be "remote programmable", and have remote sensor entries |
| 34 on the back of the unit. | 34 on the back of the unit. |
| 35 | 35 |
| 36 .. image:: {filename}/images/lambda/lpd422fm_back.jpg | 36 .. image:: {static}/images/lambda/lpd422fm_back.jpg |
| 37 :alt: Rear view of the LPD 422 FM dual regulated power supply. | 37 :alt: Rear view of the LPD 422 FM dual regulated power supply. |
| 38 | 38 |
| 39 Inside the enclosure: | 39 Inside the enclosure: |
| 40 | 40 |
| 41 .. image:: {filename}/images/lambda/lpd422fm_top.jpg | 41 .. image:: {static}/images/lambda/lpd422fm_top.jpg |
| 42 :alt: Top view of the LPD 422 FM dual regulated power supply. | 42 :alt: Top view of the LPD 422 FM dual regulated power supply. |
| 43 | 43 |
| 44 Each of the 2 power supplies have a regulator board on each side of | 44 Each of the 2 power supplies have a regulator board on each side of |
| 45 the enclosure. The power transformer is sitting at the center of the | 45 the enclosure. The power transformer is sitting at the center of the |
| 46 enclosure and shows a nice "Component Location Diagram": | 46 enclosure and shows a nice "Component Location Diagram": |
| 47 | 47 |
| 48 .. image:: {filename}/images/lambda/lpd422fm_xformer.jpg | 48 .. image:: {static}/images/lambda/lpd422fm_xformer.jpg |
| 49 :alt: The power transformer of the LPD 422 FM dual regulated power supply. | 49 :alt: The power transformer of the LPD 422 FM dual regulated power supply. |
| 50 | 50 |
| 51 A regulator board looks like: | 51 A regulator board looks like: |
| 52 | 52 |
| 53 .. image:: {filename}/images/lambda/lpd422fm_board2.jpg | 53 .. image:: {static}/images/lambda/lpd422fm_board2.jpg |
| 54 :alt: Top view of one regulator of the LPD 422 FM dual regulated | 54 :alt: Top view of one regulator of the LPD 422 FM dual regulated |
| 55 power supply. | 55 power supply. |
| 56 | 56 |
| 57 .. image:: {filename}/images/lambda/lpd422fm_board1.jpg | 57 .. image:: {static}/images/lambda/lpd422fm_board1.jpg |
| 58 :alt: Bottom view of one regulator of the LPD 422 FM dual regulated | 58 :alt: Bottom view of one regulator of the LPD 422 FM dual regulated |
| 59 power supply. | 59 power supply. |
| 60 | 60 |
| 61 The component, especially the big caps, looks like original parts and | 61 The component, especially the big caps, looks like original parts and |
| 62 the PCB is a bit burnt by the small power transistor, but nothing too | 62 the PCB is a bit burnt by the small power transistor, but nothing too |
| 68 | 68 |
| 69 Available documentations | 69 Available documentations |
| 70 ======================== | 70 ======================== |
| 71 | 71 |
| 72 - `Lambda LP, LPD & LPT series catalog | 72 - `Lambda LP, LPD & LPT series catalog |
| 73 <{filename}/pdfs/lambda/LAMBDA_LPD_LPD_LPT_series.pdf>`_ | 73 <{static}/pdfs/lambda/LAMBDA_LPD_LPD_LPT_series.pdf>`_ |
| 74 | 74 |
| 75 - `Instruction and Service Manual for Lambda LPD suffix A Series Power | 75 - `Instruction and Service Manual for Lambda LPD suffix A Series Power |
| 76 Supplies <{filename}/pdfs/lambda/LambdaLPD.pdf>`_: this is not | 76 Supplies <{static}/pdfs/lambda/LambdaLPD.pdf>`_: this is not |
| 77 exactly the same model, but it really very close. | 77 exactly the same model, but it really very close. |
| 78 | 78 |
| 79 | 79 |
| 80 | 80 |
| 81 Quick mesurements | 81 Quick mesurements |
| 84 In these quick measurements, I've not used the voltage remote sensing | 84 In these quick measurements, I've not used the voltage remote sensing |
| 85 of the power supply. | 85 of the power supply. |
| 86 | 86 |
| 87 First, a view of the noise at the output of the PSU; 0V, no load: | 87 First, a view of the noise at the output of the PSU; 0V, no load: |
| 88 | 88 |
| 89 .. image:: {filename}/images/lambda/DS1Z_QuickPrint2.png | 89 .. image:: {static}/images/lambda/DS1Z_QuickPrint2.png |
| 90 :alt: Noise level of the LPD422FM - 0V/0A | 90 :alt: Noise level of the LPD422FM - 0V/0A |
| 91 | 91 |
| 92 Same at 20V, no load: | 92 Same at 20V, no load: |
| 93 | 93 |
| 94 .. image:: {filename}/images/lambda/DS1Z_QuickPrint3.png | 94 .. image:: {static}/images/lambda/DS1Z_QuickPrint3.png |
| 95 :alt: Noise level of the LPD422FM - 20V/0A | 95 :alt: Noise level of the LPD422FM - 20V/0A |
| 96 | 96 |
| 97 And at maximum voltage (40V, no load): | 97 And at maximum voltage (40V, no load): |
| 98 | 98 |
| 99 .. image:: {filename}/images/lambda/DS1Z_QuickPrint4.png | 99 .. image:: {static}/images/lambda/DS1Z_QuickPrint4.png |
| 100 :alt: Noise level of the LPD422FM - 40V/0A | 100 :alt: Noise level of the LPD422FM - 40V/0A |
| 101 | 101 |
| 102 Then, with the `ZPB30A1 electronic load <{filename}/ZPB30A1.rst>` | 102 Then, with the `ZPB30A1 electronic load <{static}/ZPB30A1.rst>` |
| 103 connected but not consuming any current (20V, 0A): | 103 connected but not consuming any current (20V, 0A): |
| 104 | 104 |
| 105 .. image:: {filename}/images/lambda/DS1Z_QuickPrint5.png | 105 .. image:: {static}/images/lambda/DS1Z_QuickPrint5.png |
| 106 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/0A | 106 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/0A |
| 107 | 107 |
| 108 As you can see, there is a much higher injected by the electronic | 108 As you can see, there is a much higher injected by the electronic |
| 109 load. When measuring the visible pattern: | 109 load. When measuring the visible pattern: |
| 110 | 110 |
| 111 .. image:: {filename}/images/lambda/DS1Z_QuickPrint6.png | 111 .. image:: {static}/images/lambda/DS1Z_QuickPrint6.png |
| 112 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/0A | 112 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/0A |
| 113 | 113 |
| 114 it's a 20ms pattern, ie. it's the mains 50Hz being injected... Let's | 114 it's a 20ms pattern, ie. it's the mains 50Hz being injected... Let's |
| 115 turn the load on (20V, 0.5A): | 115 turn the load on (20V, 0.5A): |
| 116 | 116 |
| 117 .. image:: {filename}/images/lambda/DS1Z_QuickPrint7.png | 117 .. image:: {static}/images/lambda/DS1Z_QuickPrint7.png |
| 118 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/0.5A | 118 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/0.5A |
| 119 | 119 |
| 120 The injected noise from the mains has vanished, and the RMS noise | 120 The injected noise from the mains has vanished, and the RMS noise |
| 121 level is back to the same value as it ws with no load (around 40mV). | 121 level is back to the same value as it ws with no load (around 40mV). |
| 122 | 122 |
| 123 At 1 amp, it's roughly the same: | 123 At 1 amp, it's roughly the same: |
| 124 | 124 |
| 125 .. image:: {filename}/images/lambda/DS1Z_QuickPrint8.png | 125 .. image:: {static}/images/lambda/DS1Z_QuickPrint8.png |
| 126 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/1A | 126 :alt: Noise level of the LPD422FM connected to the ZPB30A1 - 20V/1A |
| 127 | 127 |
| 128 Now, trying to capture the transient curve when activating and | 128 Now, trying to capture the transient curve when activating and |
| 129 deactivating the load. As I cannot remote control the load, I cannot | 129 deactivating the load. As I cannot remote control the load, I cannot |
| 130 create a nice square load pattern which make this measurement much | 130 create a nice square load pattern which make this measurement much |
| 131 easier. So I've just adjusted the trigger level to single capture the | 131 easier. So I've just adjusted the trigger level to single capture the |
| 132 moment I press the 'on/off' button of the load: | 132 moment I press the 'on/off' button of the load: |
| 133 | 133 |
| 134 .. image:: {filename}/images/lambda/DS1Z_QuickPrint10.png | 134 .. image:: {static}/images/lambda/DS1Z_QuickPrint10.png |
| 135 :alt: Transient response of the LPD422FM connected to the ZPB30A1 - 20V/1A -> 0A | 135 :alt: Transient response of the LPD422FM connected to the ZPB30A1 - 20V/1A -> 0A |
| 136 | 136 |
| 137 .. image:: {filename}/images/lambda/DS1Z_QuickPrint11.png | 137 .. image:: {static}/images/lambda/DS1Z_QuickPrint11.png |
| 138 :alt: Transient response of the LPD422FM connected to the ZPB30A1 - 20V/0A -> 1A | 138 :alt: Transient response of the LPD422FM connected to the ZPB30A1 - 20V/0A -> 1A |
| 139 | 139 |
| 140 The overshoot is around 75mV and takes around 200ms to vanish, and the | 140 The overshoot is around 75mV and takes around 200ms to vanish, and the |
| 141 undershoot is a bit less (50mV) and lasts 150ms. | 141 undershoot is a bit less (50mV) and lasts 150ms. |
| 142 | 142 |
| 143 At one amp, the ripple voltage is around 8mVpp and 3mVrms: | 143 At one amp, the ripple voltage is around 8mVpp and 3mVrms: |
| 144 | 144 |
| 145 .. image:: {filename}/images/lambda/DS1Z_QuickPrint13.png | 145 .. image:: {static}/images/lambda/DS1Z_QuickPrint13.png |
| 146 :alt: Ripple voltage of the LPD422FM connected to the ZPB30A1 - 20V/1A | 146 :alt: Ripple voltage of the LPD422FM connected to the ZPB30A1 - 20V/1A |
| 147 | 147 |
| 148 It's quite out of spec: ripple should be less than 500µVrms and | 148 It's quite out of spec: ripple should be less than 500µVrms and |
| 149 1.5mVpp, but it's not really a surprise considering the age (over 40 | 149 1.5mVpp, but it's not really a surprise considering the age (over 40 |
| 150 years old!) of the PSU. A future recap may improve its performances | 150 years old!) of the PSU. A future recap may improve its performances |
